From 2047109afb5406fea9f339b0190da73e46f68175 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Mon, 22 Dec 2025 09:05:11 +0100
Subject: [PATCH 01/37] fixe scalar restart, update psi case

---
 SU2_CFD/src/output/CFlowIncOutput.cpp             |  4 ++--
 SU2_CFD/src/solvers/CSpeciesSolver.cpp            |  2 +-
 SU2_CFD/src/solvers/CTurbSolver.cpp               | 10 +++++-----
 .../py_wrapper/turbulent_premixed_psi/psi.cfg     |  4 ++--
 .../py_wrapper/turbulent_premixed_psi/run.py      | 15 ++++-----------
 5 files changed, 14 insertions(+), 21 deletions(-)

diff --git a/SU2_CFD/src/output/CFlowIncOutput.cpp b/SU2_CFD/src/output/CFlowIncOutput.cpp
index 9d408892cf6e..a7194bc2fe79 100644
--- a/SU2_CFD/src/output/CFlowIncOutput.cpp
+++ b/SU2_CFD/src/output/CFlowIncOutput.cpp
@@ -330,7 +330,7 @@ void CFlowIncOutput::SetVolumeOutputFields(CConfig *config){
     AddVolumeOutput("LAMINAR_VISCOSITY", "Laminar_Viscosity", "PRIMITIVE", "Laminar viscosity");
     AddVolumeOutput("HEAT_CAPACITY", "Heat_Capacity", "PRIMITIVE", "Heat capacity");
     AddVolumeOutput("THERMAL_CONDUCTIVITY", "Thermal_Conductivity", "PRIMITIVE", "Thermal conductivity");
-    if (heat || flamelet) AddVolumeOutput("TEMPERATURE", "Temperature", "PRIMITIVE", "Temperature");
+    AddVolumeOutput("TEMPERATURE", "Temperature", "PRIMITIVE", "Temperature");
 
     AddVolumeOutput("SKIN_FRICTION-X", "Skin_Friction_Coefficient_x", "PRIMITIVE", "x-component of the skin friction vector");
     AddVolumeOutput("SKIN_FRICTION-Y", "Skin_Friction_Coefficient_y", "PRIMITIVE", "y-component of the skin friction vector");
@@ -440,7 +440,7 @@ void CFlowIncOutput::LoadVolumeData(CConfig *config, CGeometry *geometry, CSolve
     SetVolumeOutputValue("LAMINAR_VISCOSITY", iPoint, Node_Flow->GetLaminarViscosity(iPoint));
     SetVolumeOutputValue("HEAT_CAPACITY", iPoint, Node_Flow->GetSpecificHeatCp(iPoint));
     SetVolumeOutputValue("THERMAL_CONDUCTIVITY", iPoint, Node_Flow->GetThermalConductivity(iPoint));
-    if (heat || flamelet) SetVolumeOutputValue("TEMPERATURE", iPoint, Node_Flow->GetTemperature(iPoint));
+    SetVolumeOutputValue("TEMPERATURE", iPoint, Node_Flow->GetTemperature(iPoint));
   }
 
   SetVolumeOutputValue("RES_PRESSURE", iPoint, solver[FLOW_SOL]->LinSysRes(iPoint, 0));
diff --git a/SU2_CFD/src/solvers/CSpeciesSolver.cpp b/SU2_CFD/src/solvers/CSpeciesSolver.cpp
index 3f25af7d1183..7624c9ef41d8 100644
--- a/SU2_CFD/src/solvers/CSpeciesSolver.cpp
+++ b/SU2_CFD/src/solvers/CSpeciesSolver.cpp
@@ -212,7 +212,7 @@ void CSpeciesSolver::LoadRestart(CGeometry** geometry, CSolver*** solver, CConfi
 
     /*--- for the flamelet model, the temperature is saved to file, but the energy equation is off ---*/
 
-   if (incompressible && ((!energy) && (!weakly_coupled_heat) && (!flamelet))) skipVars--;
+   if (incompressible && ((!energy) && (!weakly_coupled_heat))) skipVars--;
 
     /*--- Load data from the restart into correct containers. ---*/
 
diff --git a/SU2_CFD/src/solvers/CTurbSolver.cpp b/SU2_CFD/src/solvers/CTurbSolver.cpp
index 7d7e6fd26730..09c5f92eea14 100644
--- a/SU2_CFD/src/solvers/CTurbSolver.cpp
+++ b/SU2_CFD/src/solvers/CTurbSolver.cpp
@@ -133,7 +133,7 @@ void CTurbSolver::LoadRestart(CGeometry** geometry, CSolver*** solver, CConfig*
     const bool weakly_coupled_heat = config->GetWeakly_Coupled_Heat();
     const bool flamelet = (config->GetKind_FluidModel() == FLUID_FLAMELET);
 
-    if (incompressible && ((!energy) && (!weakly_coupled_heat) && (!flamelet))) skipVars--;
+    if (incompressible && ((!energy) && (!weakly_coupled_heat))) skipVars--;
 
     /*--- Load data from the restart into correct containers. ---*/
 
@@ -252,7 +252,7 @@ void CTurbSolver::ComputeUnderRelaxationFactorHelper(su2double allowableRatio) {
 
   /* Loop over the solution update given by relaxing the linear
    system for this nonlinear iteration. */
-  
+
   SU2_OMP_FOR_STAT(omp_chunk_size)
   for (unsigned long iPoint = 0; iPoint < nPointDomain; iPoint++) {
     su2double localUnderRelaxation = 1.0;
@@ -265,16 +265,16 @@ void CTurbSolver::ComputeUnderRelaxationFactorHelper(su2double allowableRatio) {
       turbulence variables can change over a nonlinear iteration. */
       if (ratio > allowableRatio) {
         localUnderRelaxation = min(allowableRatio / ratio, localUnderRelaxation);
-      
+
       }
     }
 
     /* Threshold the relaxation factor in the event that there is
      a very small value. This helps avoid catastrophic crashes due
      to non-realizable states by canceling the update. */
-    
+
     if (localUnderRelaxation < 1e-10) localUnderRelaxation = 0.0;
-    
+
     /* Store the under-relaxation factor for this point. */
 
     nodes->SetUnderRelaxation(iPoint, localUnderRelaxation);
diff --git a/TestCases/py_wrapper/turbulent_premixed_psi/psi.cfg b/TestCases/py_wrapper/turbulent_premixed_psi/psi.cfg
index 537eee85ce8b..5b3ecf93158e 100644
--- a/TestCases/py_wrapper/turbulent_premixed_psi/psi.cfg
+++ b/TestCases/py_wrapper/turbulent_premixed_psi/psi.cfg
@@ -31,7 +31,7 @@ INC_DENSITY_INIT= 2.55
 %
 INC_VELOCITY_INIT= (40.00, 0.0, 0.0 )
 %
-INC_ENERGY_EQUATION= YES
+INC_ENERGY_EQUATION= NO
 INC_TEMPERATURE_INIT= 673.0
 %
 INC_NONDIM= DIMENSIONAL
@@ -153,7 +153,7 @@ MARKER_ANALYZE= gas_inlet, air_axial_inlet, outlet
 MARKER_ANALYZE_AVERAGE= AREA
 %
 OUTPUT_FILES= RESTART, PARAVIEW_MULTIBLOCK
-VOLUME_OUTPUT= RESIDUAL, PRIMITIVE, SPECIES_UDS_0
+VOLUME_OUTPUT= SOLUTION, PRIMITIVE, SPECIES_UDS_0
 OUTPUT_WRT_FREQ= 100
 %
 READ_BINARY_RESTART= YES
diff --git a/TestCases/py_wrapper/turbulent_premixed_psi/run.py b/TestCases/py_wrapper/turbulent_premixed_psi/run.py
index dc1133169a24..82c72dc6e83c 100644
--- a/TestCases/py_wrapper/turbulent_premixed_psi/run.py
+++ b/TestCases/py_wrapper/turbulent_premixed_psi/run.py
@@ -91,19 +91,12 @@ def update_temperature(SU2Driver, iPoint):
     iSPECIESSOLVER = SU2Driver.GetSolverIndices()['SPECIES']
     # Note: returns a list
     C = SU2Driver.Solution(iSPECIESSOLVER)(iPoint,0)
+
     T = Tu*(1-C) + Tf*C
-    iFLOWSOLVER = SU2Driver.GetSolverIndices()['INC.FLOW']
-    # the list with names
-    solindex = getsolvar(SU2Driver)
-    primindex = SU2Driver.GetPrimitiveIndices()
-    # get Cp
-    iCp = primindex.get("CP_TOTAL")
-    Cp = SU2Driver.Primitives()(iPoint,iCp)
-    # get solution index for energy equation
-    iTEMP = solindex.get("TEMPERATURE")
-    # set enthalpy, for Ideal Gas model, enthalpy is Cp*T
-    SU2Driver.Solution(iFLOWSOLVER).Set(iPoint,iTEMP,Cp*T)
 
+    prim_indices = SU2Driver.GetPrimitiveIndices()
+    iTemp = prim_indices['TEMPERATURE']
+    SU2Driver.Primitives().Set(iPoint,iTemp, T)
 
 # ################################################################## #
 # Source term according to Zimont

From 348dee985d128f4fa6cef88c96849e2f7581733b Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Mon, 22 Dec 2025 11:22:02 +0100
Subject: [PATCH 02/37] reduce y+ warning

---
 SU2_CFD/src/solvers/CIncNSSolver.cpp | 7 ++++---
 SU2_CFD/src/solvers/CNSSolver.cpp    | 8 +++++---
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/SU2_CFD/src/solvers/CIncNSSolver.cpp b/SU2_CFD/src/solvers/CIncNSSolver.cpp
index 28747c7e1d71..383c55945ec8 100644
--- a/SU2_CFD/src/solvers/CIncNSSolver.cpp
+++ b/SU2_CFD/src/solvers/CIncNSSolver.cpp
@@ -892,14 +892,15 @@ void CIncNSSolver::SetTau_Wall_WF(CGeometry *geometry, CSolver **solver_containe
       SU2_MPI::Allreduce(&globalCounter1, &notConvergedCounter, 1, MPI_UNSIGNED_LONG, MPI_SUM, SU2_MPI::GetComm());
       SU2_MPI::Allreduce(&globalCounter2, &smallYPlusCounter, 1, MPI_UNSIGNED_LONG, MPI_SUM, SU2_MPI::GetComm());
 
-      if (rank == MASTER_NODE) {
+      const bool write_iter = (config->GetTimeIter() % config->GetVolumeOutputFrequency(0) == 0);
+      if (rank == MASTER_NODE && write_iter) {
         if (notConvergedCounter)
           cout << "Warning: Computation of wall coefficients (y+) did not converge in "
                << notConvergedCounter << " points." << endl;
 
         if (smallYPlusCounter)
-          cout << "Warning: y+ < " << config->GetwallModel_MinYPlus() << " in " << smallYPlusCounter
-               << " points, for which the wall model is not active." << endl;
+          cout << "y+ < " << config->GetwallModel_MinYPlus() << " in " << smallYPlusCounter
+               << " points. No problem, but you can increase your near-wall mesh size." << endl;
       }
     }
     END_SU2_OMP_SAFE_GLOBAL_ACCESS
diff --git a/SU2_CFD/src/solvers/CNSSolver.cpp b/SU2_CFD/src/solvers/CNSSolver.cpp
index ab90660ef22e..be79d762c7c8 100644
--- a/SU2_CFD/src/solvers/CNSSolver.cpp
+++ b/SU2_CFD/src/solvers/CNSSolver.cpp
@@ -1028,14 +1028,16 @@ void CNSSolver::SetTau_Wall_WF(CGeometry *geometry, CSolver **solver_container,
       SU2_MPI::Allreduce(&globalCounter1, &notConvergedCounter, 1, MPI_UNSIGNED_LONG, MPI_SUM, SU2_MPI::GetComm());
       SU2_MPI::Allreduce(&globalCounter2, &smallYPlusCounter, 1, MPI_UNSIGNED_LONG, MPI_SUM, SU2_MPI::GetComm());
 
-      if (rank == MASTER_NODE) {
+      const bool write_iter = (config->GetInnerIter() % config->GetVolumeOutputFrequency(0) == 0);
+
+      if (rank == MASTER_NODE && write_iter) {
         if (notConvergedCounter)
           cout << "Warning: Computation of wall coefficients (y+) did not converge in "
                << notConvergedCounter << " points." << endl;
 
         if (smallYPlusCounter)
-          cout << "Warning: y+ < " << config->GetwallModel_MinYPlus() << " in " << smallYPlusCounter
-               << " points, for which the wall model is not active." << endl;
+          cout << "y+ < " << config->GetwallModel_MinYPlus() << " in " << smallYPlusCounter
+               << " points. No problem, but you can increase your near-wallmesh size." << endl;
       }
     }
     END_SU2_OMP_SAFE_GLOBAL_ACCESS

From 1a600ed98104cece074fbf39c9fe3b2c9e0a7356 Mon Sep 17 00:00:00 2001
From: Nijso <bigfootedrockmidget@hotmail.com>
Date: Mon, 22 Dec 2025 11:22:34 +0100
Subject: [PATCH 03/37] Update SU2_CFD/src/solvers/CTurbSolver.cpp

Co-authored-by: Cristopher Morales <98025159+Cristopher-Morales@users.noreply.github.com>
---
 SU2_CFD/src/solvers/CTurbSolver.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/SU2_CFD/src/solvers/CTurbSolver.cpp b/SU2_CFD/src/solvers/CTurbSolver.cpp
index 09c5f92eea14..05f456883fb2 100644
--- a/SU2_CFD/src/solvers/CTurbSolver.cpp
+++ b/SU2_CFD/src/solvers/CTurbSolver.cpp
@@ -131,7 +131,6 @@ void CTurbSolver::LoadRestart(CGeometry** geometry, CSolver*** solver, CConfig*
     const bool incompressible = (config->GetKind_Regime() == ENUM_REGIME::INCOMPRESSIBLE);
     const bool energy = config->GetEnergy_Equation();
     const bool weakly_coupled_heat = config->GetWeakly_Coupled_Heat();
-    const bool flamelet = (config->GetKind_FluidModel() == FLUID_FLAMELET);
 
     if (incompressible && ((!energy) && (!weakly_coupled_heat))) skipVars--;
 

From 5a0a2f69015d15af76d58c11782cf8d1e2164268 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Mon, 22 Dec 2025 11:45:06 +0100
Subject: [PATCH 04/37] fix weakly coupled heat restart

---
 SU2_CFD/src/output/CFlowIncOutput.cpp | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/SU2_CFD/src/output/CFlowIncOutput.cpp b/SU2_CFD/src/output/CFlowIncOutput.cpp
index a7194bc2fe79..e935fba2f1e1 100644
--- a/SU2_CFD/src/output/CFlowIncOutput.cpp
+++ b/SU2_CFD/src/output/CFlowIncOutput.cpp
@@ -305,6 +305,7 @@ void CFlowIncOutput::SetVolumeOutputFields(CConfig *config){
   AddVolumeOutput("VELOCITY-Y", "Velocity_y", "SOLUTION", "y-component of the velocity vector");
   if (nDim == 3)
     AddVolumeOutput("VELOCITY-Z", "Velocity_z", "SOLUTION", "z-component of the velocity vector");
+
   if (weakly_coupled_heat) AddVolumeOutput("TEMPERATURE", "Temperature", "SOLUTION", "Temperature");
   if (heat) AddVolumeOutput("ENTHALPY", "Enthalpy", "SOLUTION", "Enthalpy");
 
@@ -330,7 +331,8 @@ void CFlowIncOutput::SetVolumeOutputFields(CConfig *config){
     AddVolumeOutput("LAMINAR_VISCOSITY", "Laminar_Viscosity", "PRIMITIVE", "Laminar viscosity");
     AddVolumeOutput("HEAT_CAPACITY", "Heat_Capacity", "PRIMITIVE", "Heat capacity");
     AddVolumeOutput("THERMAL_CONDUCTIVITY", "Thermal_Conductivity", "PRIMITIVE", "Thermal conductivity");
-    AddVolumeOutput("TEMPERATURE", "Temperature", "PRIMITIVE", "Temperature");
+    if (!weakly_coupled_heat)
+      AddVolumeOutput("TEMPERATURE", "Temperature", "PRIMITIVE", "Temperature");
 
     AddVolumeOutput("SKIN_FRICTION-X", "Skin_Friction_Coefficient_x", "PRIMITIVE", "x-component of the skin friction vector");
     AddVolumeOutput("SKIN_FRICTION-Y", "Skin_Friction_Coefficient_y", "PRIMITIVE", "y-component of the skin friction vector");
@@ -354,7 +356,7 @@ void CFlowIncOutput::SetVolumeOutputFields(CConfig *config){
   AddVolumeOutput("RES_VELOCITY-Y", "Residual_Velocity_y", "RESIDUAL", "Residual of the y-velocity component");
   if (nDim == 3)
     AddVolumeOutput("RES_VELOCITY-Z", "Residual_Velocity_z", "RESIDUAL", "Residual of the z-velocity component");
-  if (config->GetEnergy_Equation()){
+  if (heat){
     AddVolumeOutput("RES_ENTHALPY", "Residual_Enthalpy", "RESIDUAL", "Residual of the enthalpy");
   }
   SetVolumeOutputFieldsScalarResidual(config);
@@ -417,6 +419,7 @@ void CFlowIncOutput::LoadVolumeData(CConfig *config, CGeometry *geometry, CSolve
   if (heat) {
     SetVolumeOutputValue("ENTHALPY", iPoint, Node_Flow->GetSolution(iPoint, nDim+1));
   }
+
   if (weakly_coupled_heat) SetVolumeOutputValue("TEMPERATURE", iPoint, Node_Heat->GetSolution(iPoint, 0));
 
   // Radiation solver
@@ -440,7 +443,8 @@ void CFlowIncOutput::LoadVolumeData(CConfig *config, CGeometry *geometry, CSolve
     SetVolumeOutputValue("LAMINAR_VISCOSITY", iPoint, Node_Flow->GetLaminarViscosity(iPoint));
     SetVolumeOutputValue("HEAT_CAPACITY", iPoint, Node_Flow->GetSpecificHeatCp(iPoint));
     SetVolumeOutputValue("THERMAL_CONDUCTIVITY", iPoint, Node_Flow->GetThermalConductivity(iPoint));
-    SetVolumeOutputValue("TEMPERATURE", iPoint, Node_Flow->GetTemperature(iPoint));
+    if (!weakly_coupled_heat)
+      SetVolumeOutputValue("TEMPERATURE", iPoint, Node_Flow->GetTemperature(iPoint));
   }
 
   SetVolumeOutputValue("RES_PRESSURE", iPoint, solver[FLOW_SOL]->LinSysRes(iPoint, 0));

From 5ba6371fba20e432f13e21d24e07b62cd2aef25b Mon Sep 17 00:00:00 2001
From: Nijso <bigfootedrockmidget@hotmail.com>
Date: Mon, 22 Dec 2025 11:46:36 +0100
Subject: [PATCH 05/37] Apply suggestion from @bigfooted

---
 SU2_CFD/src/output/CFlowIncOutput.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/SU2_CFD/src/output/CFlowIncOutput.cpp b/SU2_CFD/src/output/CFlowIncOutput.cpp
index e935fba2f1e1..972181e32600 100644
--- a/SU2_CFD/src/output/CFlowIncOutput.cpp
+++ b/SU2_CFD/src/output/CFlowIncOutput.cpp
@@ -305,7 +305,6 @@ void CFlowIncOutput::SetVolumeOutputFields(CConfig *config){
   AddVolumeOutput("VELOCITY-Y", "Velocity_y", "SOLUTION", "y-component of the velocity vector");
   if (nDim == 3)
     AddVolumeOutput("VELOCITY-Z", "Velocity_z", "SOLUTION", "z-component of the velocity vector");
-
   if (weakly_coupled_heat) AddVolumeOutput("TEMPERATURE", "Temperature", "SOLUTION", "Temperature");
   if (heat) AddVolumeOutput("ENTHALPY", "Enthalpy", "SOLUTION", "Enthalpy");
 

From 03b9484a526878b715d043bac7b07c05e14f1a37 Mon Sep 17 00:00:00 2001
From: Nijso <bigfootedrockmidget@hotmail.com>
Date: Mon, 22 Dec 2025 11:47:01 +0100
Subject: [PATCH 06/37] Apply suggestion from @bigfooted

---
 SU2_CFD/src/output/CFlowIncOutput.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/SU2_CFD/src/output/CFlowIncOutput.cpp b/SU2_CFD/src/output/CFlowIncOutput.cpp
index 972181e32600..f27c77cf5569 100644
--- a/SU2_CFD/src/output/CFlowIncOutput.cpp
+++ b/SU2_CFD/src/output/CFlowIncOutput.cpp
@@ -418,7 +418,6 @@ void CFlowIncOutput::LoadVolumeData(CConfig *config, CGeometry *geometry, CSolve
   if (heat) {
     SetVolumeOutputValue("ENTHALPY", iPoint, Node_Flow->GetSolution(iPoint, nDim+1));
   }
-
   if (weakly_coupled_heat) SetVolumeOutputValue("TEMPERATURE", iPoint, Node_Heat->GetSolution(iPoint, 0));
 
   // Radiation solver

From 43af7123173da9ae6a83e3a625baccba28754a0a Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Mon, 22 Dec 2025 13:00:22 +0100
Subject: [PATCH 07/37] remove unused var

---
 SU2_CFD/src/solvers/CSpeciesSolver.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/SU2_CFD/src/solvers/CSpeciesSolver.cpp b/SU2_CFD/src/solvers/CSpeciesSolver.cpp
index 7624c9ef41d8..88469650ab0c 100644
--- a/SU2_CFD/src/solvers/CSpeciesSolver.cpp
+++ b/SU2_CFD/src/solvers/CSpeciesSolver.cpp
@@ -207,7 +207,6 @@ void CSpeciesSolver::LoadRestart(CGeometry** geometry, CSolver*** solver, CConfi
 
     const bool incompressible = (config->GetKind_Regime() == ENUM_REGIME::INCOMPRESSIBLE);
     const bool energy = config->GetEnergy_Equation();
-    const bool flamelet = (config->GetKind_FluidModel() == FLUID_FLAMELET);
     const bool weakly_coupled_heat = config->GetWeakly_Coupled_Heat();
 
     /*--- for the flamelet model, the temperature is saved to file, but the energy equation is off ---*/

From ae9d43fe26cc7d9909c5d9769f0cb04b65a314c0 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Mon, 22 Dec 2025 23:24:24 +0100
Subject: [PATCH 08/37] fix mass diffusivity MPI bug

---
 SU2_CFD/src/fluid/CFluidScalar.cpp     | 1 +
 SU2_CFD/src/solvers/CSpeciesSolver.cpp | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/SU2_CFD/src/fluid/CFluidScalar.cpp b/SU2_CFD/src/fluid/CFluidScalar.cpp
index b42cf7b70433..dcf54f2f3366 100644
--- a/SU2_CFD/src/fluid/CFluidScalar.cpp
+++ b/SU2_CFD/src/fluid/CFluidScalar.cpp
@@ -282,4 +282,5 @@ void CFluidScalar::SetTDState_h(const su2double val_enthalpy, const su2double* v
   }
 
   Kt = WilkeConductivity(val_scalars);
+  ComputeMassDiffusivity();
 }
diff --git a/SU2_CFD/src/solvers/CSpeciesSolver.cpp b/SU2_CFD/src/solvers/CSpeciesSolver.cpp
index 88469650ab0c..e04c55ef1dc6 100644
--- a/SU2_CFD/src/solvers/CSpeciesSolver.cpp
+++ b/SU2_CFD/src/solvers/CSpeciesSolver.cpp
@@ -302,6 +302,8 @@ void CSpeciesSolver::Preprocessing(CGeometry* geometry, CSolver** solver_contain
     const su2double* scalar = solver_container[SPECIES_SOL]->GetNodes()->GetSolution(iPoint);
     solver_container[FLOW_SOL]->GetFluidModel()->SetMassDiffusivityModel(config);
     solver_container[FLOW_SOL]->GetFluidModel()->SetTDState_T(temperature, scalar);
+    /*--- Recompute viscosity, important  to get diffusivity correct across MPI ranks. ---*/
+    const su2double viscosity =  solver_container[FLOW_SOL]->GetFluidModel()->GetLaminarViscosity();
     for (auto iVar = 0u; iVar <= nVar; iVar++) {
       const su2double mass_diffusivity = solver_container[FLOW_SOL]->GetFluidModel()->GetMassDiffusivity(iVar);
       nodes->SetDiffusivity(iPoint, mass_diffusivity, iVar);

From 3ac3d640033096a8397b2fa45e35eff0d9a6554a Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Tue, 23 Dec 2025 09:35:00 +0100
Subject: [PATCH 09/37] use enthalpy for computing temperature also when energy
 is off

---
 SU2_CFD/src/variables/CIncNSVariable.cpp | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/SU2_CFD/src/variables/CIncNSVariable.cpp b/SU2_CFD/src/variables/CIncNSVariable.cpp
index e31109fcd662..b3632071f17e 100644
--- a/SU2_CFD/src/variables/CIncNSVariable.cpp
+++ b/SU2_CFD/src/variables/CIncNSVariable.cpp
@@ -65,12 +65,10 @@ bool CIncNSVariable::SetPrimVar(unsigned long iPoint, su2double eddy_visc, su2do
     FluidModel->SetTDState_h(Enthalpy, scalar);
     Temperature = FluidModel->GetTemperature();
   } else {
-    /*--- When energy equation is switch off, a constant temperature is imposed, and enthalpy is recomputed based on
-     * this temperature. As in the fluid flamelet model, the temperature is retrieved from a look-up table, then the
-     * temperature is obtained directly from the fluidmodel. For the other fluid models, GetTemperature provides the
-     * same value as TemperatureInc ---*/
-    FluidModel->SetTDState_T(TemperatureInc, scalar);
-    Enthalpy = Solution(iPoint, nDim + 1) = FluidModel->GetEnthalpy();
+    /*--- When energy equation is switched off, use enthalpy from solution to compute temperature.
+     * This allows Python wrapper updates to enthalpy to correctly update the density. ---*/
+    Enthalpy = Solution(iPoint, nDim + 1);
+    FluidModel->SetTDState_h(Enthalpy, scalar);
     Temperature = FluidModel->GetTemperature();
   }
   auto check_temp = SetTemperature(iPoint, Temperature, TemperatureLimits);

From 0e0d08acedea096e932f45e1b5f02c6907184263 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Tue, 23 Dec 2025 21:31:09 +0100
Subject: [PATCH 10/37] fix sensible enthalpy

---
 Common/include/CConfig.hpp                    |  7 -----
 Common/include/option_structure.hpp           |  2 +-
 Common/src/CConfig.cpp                        |  3 --
 SU2_CFD/include/fluid/CConstantDensity.hpp    |  6 ++--
 SU2_CFD/include/fluid/CFluidScalar.hpp        |  3 +-
 SU2_CFD/include/fluid/CIncIdealGas.hpp        |  4 +--
 .../include/fluid/CIncIdealGasPolynomial.hpp  |  3 +-
 SU2_CFD/src/fluid/CFluidScalar.cpp            |  9 +++---
 SU2_CFD/src/solvers/CIncEulerSolver.cpp       |  4 +--
 SU2_CFD/src/variables/CIncEulerVariable.cpp   | 11 ++++----
 SU2_CFD/src/variables/CIncNSVariable.cpp      | 22 ++++++---------
 .../py_wrapper/turbulent_premixed_psi/psi.cfg | 28 ++++++++++++-------
 .../py_wrapper/turbulent_premixed_psi/run.py  | 26 +++++++++++++----
 13 files changed, 67 insertions(+), 61 deletions(-)

diff --git a/Common/include/CConfig.hpp b/Common/include/CConfig.hpp
index 8abcc77e4fbe..794622bb1a1e 100644
--- a/Common/include/CConfig.hpp
+++ b/Common/include/CConfig.hpp
@@ -919,7 +919,6 @@ class CConfig {
   Initial_BCThrust,                /*!< \brief Ratio of turbulent to laminar viscosity at the actuator disk. */
   Pressure_FreeStream,             /*!< \brief Total pressure of the fluid. */
   Pressure_Thermodynamic,          /*!< \brief Thermodynamic pressure of the fluid. */
-  Standard_Ref_Temperature,        /*!< \brief Standard reference temperature for multicomponent flows. */
   Temperature_FreeStream,          /*!< \brief Total temperature of the fluid.  */
   Temperature_ve_FreeStream;       /*!< \brief Total vibrational-electronic temperature of the fluid.  */
   unsigned short wallModel_MaxIter; /*!< \brief maximum number of iterations for the Newton method for the wall model */
@@ -1959,12 +1958,6 @@ class CConfig {
    */
   su2double GetPressure_Thermodynamic(void) const { return Pressure_Thermodynamic; }
 
-  /*!
-   * \brief Get the value of the standard reference temperature for multicomponent flows.
-   * \return Standard reference temperature, Non-dimensionalized if it is needed for Non-Dimensional problems.
-   */
-  su2double GetStandard_RefTemperatureND(void) const { return Standard_Ref_Temperature / Temperature_Ref; }
-
   /*!
    * \brief Get the value of the non-dimensionalized thermodynamic pressure.
    * \return Non-dimensionalized thermodynamic pressure.
diff --git a/Common/include/option_structure.hpp b/Common/include/option_structure.hpp
index bf99257b1387..f42547fe1f6b 100644
--- a/Common/include/option_structure.hpp
+++ b/Common/include/option_structure.hpp
@@ -96,7 +96,7 @@ const su2double UNIVERSAL_GAS_CONSTANT = 8.3144598;   /*!< \brief Universal gas
 const su2double BOLTZMANN_CONSTANT = 1.3806503E-23;   /*!< \brief Boltzmann's constant [J K^-1] */
 const su2double AVOGAD_CONSTANT = 6.0221415E26; /*!< \brief Avogadro's constant, number of particles in one kmole. */
 const su2double FUND_ELEC_CHARGE_CGS = 4.8032047E-10; /*!< \brief Fundamental electric charge in CGS units, cm^(3/2) g^(1/2) s^(-1). */
-
+const su2double STD_REF_TEMP = 298.15;  /*!< \brief Standard reference temperature for enthalpy in Kelvin. */
 const su2double EPS = 1.0E-16;        /*!< \brief Error scale. */
 const su2double TURB_EPS = 1.0E-16;   /*!< \brief Turbulent Error scale. */
 
diff --git a/Common/src/CConfig.cpp b/Common/src/CConfig.cpp
index 8a84e679ab69..c37a471be58e 100644
--- a/Common/src/CConfig.cpp
+++ b/Common/src/CConfig.cpp
@@ -1229,9 +1229,6 @@ void CConfig::SetConfig_Options() {
   addDoubleOption("GAMMA_VALUE", Gamma, 1.4);
   /*!\brief THERMODYNAMIC_PRESSURE  \n DESCRIPTION: Thermodynamics(operating) Pressure (101325 Pa), only for incompressible flows) \ingroup Config*/
   addDoubleOption("THERMODYNAMIC_PRESSURE", Pressure_Thermodynamic, 101325.0);
-  /*!\brief STANDARD_REFERENCE_TEMPERATURE  \n DESCRIPTION: Standard reference temperature (298.15K), only for
-   * multicomponent incompressible flows) \ingroup Config*/
-  addDoubleOption("STANDARD_REFERENCE_TEMPERATURE", Standard_Ref_Temperature, 298.15);
   /*!\brief CP_VALUE  \n DESCRIPTION: Specific heat at constant pressure, Cp (1004.703 J/kg*K (air), constant density incompressible fluids only) \ingroup Config*/
   addDoubleListOption("SPECIFIC_HEAT_CP", nSpecific_Heat_Cp, Specific_Heat_Cp);
   /*!\brief THERMAL_EXPANSION_COEFF  \n DESCRIPTION: Thermal expansion coefficient (0.00347 K^-1 (air), used for Boussinesq approximation for liquids/non-ideal gases) \ingroup Config*/
diff --git a/SU2_CFD/include/fluid/CConstantDensity.hpp b/SU2_CFD/include/fluid/CConstantDensity.hpp
index acfeed2e0cf0..a796762a2713 100644
--- a/SU2_CFD/include/fluid/CConstantDensity.hpp
+++ b/SU2_CFD/include/fluid/CConstantDensity.hpp
@@ -56,16 +56,16 @@ class CConstantDensity final : public CFluidModel {
        decoupled equation. Hence, we update the value.
        Note Cp = Cv, (gamma = 1).*/
     Temperature = t;
-    Enthalpy = Cp * Temperature;
+    Enthalpy = Cp * (Temperature - STD_REF_TEMP);  // Sensible enthalpy relative to STD_REF_TEMP
   }
 
   /*!
    * \brief Set the Dimensionless State using Enthalpy.
    * \param[in] val_enthalpy - Enthalpy value at the point.
-   * \param[in] val_scalars - not used here. 
+   * \param[in] val_scalars - not used here.
    */
   void SetTDState_h(su2double val_enthalpy, const su2double* val_scalars = nullptr) override {
     Enthalpy = val_enthalpy;
-    Temperature = Enthalpy / Cp;
+    Temperature = Enthalpy / Cp + STD_REF_TEMP;  // Temperature from sensible enthalpy
   }
 };
diff --git a/SU2_CFD/include/fluid/CFluidScalar.hpp b/SU2_CFD/include/fluid/CFluidScalar.hpp
index 164043872d6a..ba97fa5451e4 100644
--- a/SU2_CFD/include/fluid/CFluidScalar.hpp
+++ b/SU2_CFD/include/fluid/CFluidScalar.hpp
@@ -42,7 +42,6 @@ class CFluidScalar final : public CFluidModel {
   const int n_species_mixture;            /*!< \brief Number of species in mixture. */
   su2double Gas_Constant;                 /*!< \brief Specific gas constant. */
   const su2double Pressure_Thermodynamic; /*!< \brief Constant pressure thermodynamic. */
-  const su2double Ref_Temperature;        /*!< \brief Standard Reference temperature, usually set to 298.15 K. */
   const su2double GasConstant_Ref;        /*!< \brief Gas constant reference needed for Nondimensional problems. */
   const su2double Prandtl_Turb_Number;    /*!< \brief Prandlt turbulent number.*/
   const su2double Schmidt_Turb_Number;    /*!< \brief Schmidt turbulent number.*/
@@ -177,7 +176,7 @@ class CFluidScalar final : public CFluidModel {
   /*!
    * \brief Virtual member.
    * \param[in] val_enthalpy - Enthalpy value at the point.
-   * \param[in] val_scalars - Scalar mass fractions. 
+   * \param[in] val_scalars - Scalar mass fractions.
    */
   void SetTDState_h(su2double val_enthalpy, const su2double* val_scalars = nullptr) override;
 };
diff --git a/SU2_CFD/include/fluid/CIncIdealGas.hpp b/SU2_CFD/include/fluid/CIncIdealGas.hpp
index 16266e569568..4b35735f096d 100644
--- a/SU2_CFD/include/fluid/CIncIdealGas.hpp
+++ b/SU2_CFD/include/fluid/CIncIdealGas.hpp
@@ -58,7 +58,7 @@ class CIncIdealGas final : public CFluidModel {
     /*--- The EoS only depends upon temperature. ---*/
     Temperature = t;
     Density = Pressure / (Temperature * Gas_Constant);
-    Enthalpy = Cp * Temperature;
+    Enthalpy = Cp * (Temperature - STD_REF_TEMP);  // Sensible enthalpy relative to REF_TEMP
   }
 
   /*!
@@ -67,7 +67,7 @@ class CIncIdealGas final : public CFluidModel {
    */
   void SetTDState_h(su2double val_enthalpy, const su2double* val_scalars = nullptr) override {
     Enthalpy = val_enthalpy;
-    Temperature = Enthalpy / Cp;
+    Temperature = Enthalpy / Cp + STD_REF_TEMP;  // Temperature from sensible enthalpy
     Density = Pressure / (Temperature * Gas_Constant);
   }
 
diff --git a/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp b/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
index e1f5f1d9105c..aff8085617d9 100644
--- a/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
+++ b/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
@@ -58,11 +58,10 @@ class CIncIdealGasPolynomial final : public CFluidModel {
    * \param[in] config - configuration container for the problem.
    */
   void SetCpModel(const CConfig* config) override {
-    const su2double t_ref = config->GetStandard_RefTemperatureND();
     Enthalpy_Ref = 0.0;
     su2double t_i = 1.0;
     for (int i = 0; i < N; ++i) {
-      t_i *= t_ref;
+      t_i *= STD_REF_TEMP;
       coeffs_[i] = config->GetCp_PolyCoeffND(i);
       Enthalpy_Ref += coeffs_[i] * t_i / (i + 1);
     }
diff --git a/SU2_CFD/src/fluid/CFluidScalar.cpp b/SU2_CFD/src/fluid/CFluidScalar.cpp
index dcf54f2f3366..4b384c521f9c 100644
--- a/SU2_CFD/src/fluid/CFluidScalar.cpp
+++ b/SU2_CFD/src/fluid/CFluidScalar.cpp
@@ -45,7 +45,6 @@ CFluidScalar::CFluidScalar(su2double value_pressure_operating, const CConfig* co
     : CFluidModel(),
       n_species_mixture(config->GetnSpecies() + 1),
       Pressure_Thermodynamic(value_pressure_operating),
-      Ref_Temperature(config->GetStandard_RefTemperatureND()),
       GasConstant_Ref(config->GetGas_Constant_Ref()),
       Prandtl_Turb_Number(config->GetPrandtl_Turb()),
       Schmidt_Turb_Number(config->GetSchmidt_Number_Turbulent()),
@@ -219,14 +218,14 @@ su2double CFluidScalar::ComputeEnthalpyFromT(const su2double val_temperature, co
    * depend on temperature, but it does depend on mixture composition, enthalpy is directly computed from
    * the expression h_s = Cp(T - T_ref).
    */
-  su2double val_Enthalpy = Cp * (val_temperature - Ref_Temperature);
+  su2double val_Enthalpy = Cp * (val_temperature - STD_REF_TEMP);
   return val_Enthalpy;
 }
 
 void CFluidScalar::GetEnthalpyDiffusivity(su2double* enthalpy_diffusions) const {
-  const su2double enthalpy_species_N = specificHeat[n_species_mixture - 1] * (Temperature - Ref_Temperature);
+  const su2double enthalpy_species_N = specificHeat[n_species_mixture - 1] * (Temperature - STD_REF_TEMP);
   for (int iVar = 0; iVar < n_species_mixture - 1; iVar++) {
-    const su2double enthalpy_species_i = specificHeat[iVar] * (Temperature - Ref_Temperature);
+    const su2double enthalpy_species_i = specificHeat[iVar] * (Temperature - STD_REF_TEMP);
     enthalpy_diffusions[iVar] = Density * (enthalpy_species_i * massDiffusivity[iVar] -
                                            enthalpy_species_N * massDiffusivity[n_species_mixture - 1]);
     enthalpy_diffusions[iVar] += Mu_Turb * (enthalpy_species_i - enthalpy_species_N) / Schmidt_Turb_Number;
@@ -271,7 +270,7 @@ void CFluidScalar::SetTDState_h(const su2double val_enthalpy, const su2double* v
    * depend on temperature, but it does depend on mixture composition, temperature is directly solved from the
    * expression h_s = Cp(T - T_ref).
    */
-  Temperature = val_enthalpy / Cp + Ref_Temperature;
+  Temperature = val_enthalpy / Cp + STD_REF_TEMP;
   Density = Pressure_Thermodynamic / (Temperature * Gas_Constant);
   Cv = Cp - Gas_Constant;
 
diff --git a/SU2_CFD/src/solvers/CIncEulerSolver.cpp b/SU2_CFD/src/solvers/CIncEulerSolver.cpp
index 956af94ab58d..b9d8c013bb65 100644
--- a/SU2_CFD/src/solvers/CIncEulerSolver.cpp
+++ b/SU2_CFD/src/solvers/CIncEulerSolver.cpp
@@ -2145,9 +2145,9 @@ void CIncEulerSolver::SetPreconditioner(const CConfig *config, unsigned long iPo
      Therefore, we build inv(Precon) here and multiply by the residual
      later in the R-K and Euler Explicit time integration schemes. ---*/
 
-    
+
     Preconditioner[0][0] = Enthalpy * BetaInc2 * dRhodh / Density + BetaInc2;
-    
+
     for (iDim = 0; iDim < nDim; iDim++) Preconditioner[iDim + 1][0] = -1.0 * Velocity[iDim] / Density;
 
     if (energy) {
diff --git a/SU2_CFD/src/variables/CIncEulerVariable.cpp b/SU2_CFD/src/variables/CIncEulerVariable.cpp
index 881de86562e4..0c117127c8b6 100644
--- a/SU2_CFD/src/variables/CIncEulerVariable.cpp
+++ b/SU2_CFD/src/variables/CIncEulerVariable.cpp
@@ -75,11 +75,10 @@ bool CIncEulerVariable::SetPrimVar(unsigned long iPoint, CFluidModel *FluidModel
 
   SetPressure(iPoint);
 
-  /*--- Set the value of the enthalpy directly ---*/
-
   su2double Enthalpy = Solution(iPoint, nDim +1);
   FluidModel->SetTDState_h(Enthalpy);
   su2double Temperature = FluidModel->GetTemperature();
+
   const auto check_temp = SetTemperature(iPoint, Temperature, TemperatureLimits);
 
   /*--- Use the fluid model to compute the new value of density.
@@ -103,8 +102,7 @@ bool CIncEulerVariable::SetPrimVar(unsigned long iPoint, CFluidModel *FluidModel
 
     Enthalpy = Solution(iPoint, nDim+1);
     FluidModel->SetTDState_h(Enthalpy);
-    Temperature = FluidModel->GetTemperature();
-    SetTemperature(iPoint, Temperature, TemperatureLimits);
+    SetTemperature(iPoint, FluidModel->GetTemperature(), TemperatureLimits);
     SetDensity(iPoint, FluidModel->GetDensity());
 
     /*--- Flag this point as non-physical. ---*/
@@ -117,10 +115,13 @@ bool CIncEulerVariable::SetPrimVar(unsigned long iPoint, CFluidModel *FluidModel
 
   SetVelocity(iPoint);
 
-  /*--- Set enthalpy and specific heats (only necessary for consistency with preconditioning). ---*/
+  /*--- Set specific heats ---*/
 
   SetSpecificHeatCp(iPoint, FluidModel->GetCp());
   SetSpecificHeatCv(iPoint, FluidModel->GetCv());
+
+  /*--- Set enthalpy ---*/
+
   SetEnthalpy(iPoint, FluidModel->GetEnthalpy());
 
   return physical;
diff --git a/SU2_CFD/src/variables/CIncNSVariable.cpp b/SU2_CFD/src/variables/CIncNSVariable.cpp
index b3632071f17e..3725846d1aa8 100644
--- a/SU2_CFD/src/variables/CIncNSVariable.cpp
+++ b/SU2_CFD/src/variables/CIncNSVariable.cpp
@@ -53,26 +53,21 @@ CIncNSVariable::CIncNSVariable(su2double pressure, const su2double *velocity, su
 bool CIncNSVariable::SetPrimVar(unsigned long iPoint, su2double eddy_visc, su2double turb_ke, CFluidModel *FluidModel, const su2double *scalar) {
 
   bool physical = true;
-  su2double Temperature;
-  su2double Enthalpy;
 
   /*--- Set the value of the pressure ---*/
 
   SetPressure(iPoint);
 
-  if (Energy) {
-    Enthalpy = Solution(iPoint, nDim + 1);
-    FluidModel->SetTDState_h(Enthalpy, scalar);
-    Temperature = FluidModel->GetTemperature();
-  } else {
-    /*--- When energy equation is switched off, use enthalpy from solution to compute temperature.
-     * This allows Python wrapper updates to enthalpy to correctly update the density. ---*/
-    Enthalpy = Solution(iPoint, nDim + 1);
-    FluidModel->SetTDState_h(Enthalpy, scalar);
-    Temperature = FluidModel->GetTemperature();
-  }
+  su2double Enthalpy = Solution(iPoint, nDim + 1);
+  FluidModel->SetTDState_h(Enthalpy, scalar);
+  su2double Temperature = FluidModel->GetTemperature();
+
   auto check_temp = SetTemperature(iPoint, Temperature, TemperatureLimits);
 
+  /*--- Use the fluid model to compute the new value of density.
+  Note that the thermodynamic pressure is constant and decoupled
+  from the dynamic pressure being iterated. ---*/
+
   /*--- Set the value of the density ---*/
 
   const auto check_dens = SetDensity(iPoint, FluidModel->GetDensity());
@@ -91,7 +86,6 @@ bool CIncNSVariable::SetPrimVar(unsigned long iPoint, su2double eddy_visc, su2do
     Enthalpy = Solution(iPoint, nDim + 1);
     FluidModel->SetTDState_h(Enthalpy, scalar);
     SetTemperature(iPoint, FluidModel->GetTemperature(), TemperatureLimits);
-
     SetDensity(iPoint, FluidModel->GetDensity());
 
     /*--- Flag this point as non-physical. ---*/
diff --git a/TestCases/py_wrapper/turbulent_premixed_psi/psi.cfg b/TestCases/py_wrapper/turbulent_premixed_psi/psi.cfg
index 5b3ecf93158e..c01c2de84cb1 100644
--- a/TestCases/py_wrapper/turbulent_premixed_psi/psi.cfg
+++ b/TestCases/py_wrapper/turbulent_premixed_psi/psi.cfg
@@ -25,7 +25,6 @@ FREESTREAM_TEMPERATURE = 673
 FREESTREAM_DENSITY = 2.55
 % ---------------- INCOMPRESSIBLE FLOW CONDITION DEFINITION -------------------%
 %
-%INC_DENSITY_MODEL= CONSTANT
 INC_DENSITY_MODEL= VARIABLE
 INC_DENSITY_INIT= 2.55
 %
@@ -41,20 +40,26 @@ INC_NONDIM= DIMENSIONAL
 %FLUID_MODEL= CONSTANT_DENSITY
 FLUID_MODEL= INC_IDEAL_GAS
 %
-CONDUCTIVITY_MODEL= CONSTANT_CONDUCTIVITY
-THERMAL_CONDUCTIVITY_CONSTANT= 0.0357
+CONDUCTIVITY_MODEL= CONSTANT_PRANDTL
+%THERMAL_CONDUCTIVITY_CONSTANT= 0.0357
 %
 PRANDTL_LAM= 0.72
-TURBULENT_CONDUCTIVITY_MODEL= NONE
+TURBULENT_CONDUCTIVITY_MODEL= CONSTANT_PRANDTL_TURB
+%TURBULENT_CONDUCTIVITY_MODEL= NONE 
 PRANDTL_TURB= 0.90
 %
-VISCOSITY_MODEL= SUTHERLAND
+%VISCOSITY_MODEL= SUTHERLAND
+VISCOSITY_MODEL= POLYNOMIAL_VISCOSITY 
+% polynomial viscosity for methane-air (phi=0.50) 
+MU_POLYCOEFFS= (1.097e-5, 3.437e-8, 3.332e-12, 0, 0)
+
+
 MU_CONSTANT=  1.716E-5
 MU_REF = 1.716e-5
 MU_T_REF= 273.15
 SUTHERLAND_CONSTANT = 110.4
 
-SPECIFIC_HEAT_CP = 1150
+SPECIFIC_HEAT_CP = 1350
 %
 % -------------------- BOUNDARY CONDITION DEFINITION --------------------------%
 %
@@ -108,9 +113,12 @@ TIME_DISCRE_FLOW= EULER_IMPLICIT
 % -------------------- SCALAR TRANSPORT ---------------------------------------%
 %
 KIND_SCALAR_MODEL= SPECIES_TRANSPORT
-DIFFUSIVITY_MODEL= CONSTANT_DIFFUSIVITY
+%DIFFUSIVITY_MODEL= CONSTANT_DIFFUSIVITY
+DIFFUSIVITY_MODEL= CONSTANT_SCHMIDT
+%DIFFUSIVITY_MODEL= CONSTANT_LEWIS
 SCHMIDT_NUMBER_LAMINAR= 1.0
-DIFFUSIVITY_CONSTANT= 7.56e-5
+CONSTANT_LEWIS_NUMBER= 1.0 1.0
+DIFFUSIVITY_CONSTANT= 5.0e-5
 
 % according to the paper
 SCHMIDT_NUMBER_TURBULENT= 0.7
@@ -152,8 +160,8 @@ CONV_FILENAME= history
 MARKER_ANALYZE= gas_inlet, air_axial_inlet, outlet
 MARKER_ANALYZE_AVERAGE= AREA
 %
-OUTPUT_FILES= RESTART, PARAVIEW_MULTIBLOCK
-VOLUME_OUTPUT= SOLUTION, PRIMITIVE, SPECIES_UDS_0
+OUTPUT_FILES= RESTART, RESTART_ASCII, PARAVIEW_MULTIBLOCK
+VOLUME_OUTPUT= RESIDUAL, PRIMITIVE, SPECIES_UDS_0
 OUTPUT_WRT_FREQ= 100
 %
 READ_BINARY_RESTART= YES
diff --git a/TestCases/py_wrapper/turbulent_premixed_psi/run.py b/TestCases/py_wrapper/turbulent_premixed_psi/run.py
index 82c72dc6e83c..8097c8b08fa1 100644
--- a/TestCases/py_wrapper/turbulent_premixed_psi/run.py
+++ b/TestCases/py_wrapper/turbulent_premixed_psi/run.py
@@ -36,6 +36,7 @@
 # without mpi:
 #  comm = 0
 
+Tref = 298.15
 # flame temperature of the methane-air mixture (phi=0.5, P=5)
 Tf = 1777
 
@@ -48,7 +49,7 @@
 # unburnt thermal conductivity of methane-air (phi=0.5, P=5)
 k_u = 0.0523
 # unburnt heat capacity of methane-air (phi=0.5, P=5)
-cp_u = 1311.0
+cp_u = 1350.0
 
 # P = rho*R*T
 # 5 = 2.55 * R * 673
@@ -91,12 +92,25 @@ def update_temperature(SU2Driver, iPoint):
     iSPECIESSOLVER = SU2Driver.GetSolverIndices()['SPECIES']
     # Note: returns a list
     C = SU2Driver.Solution(iSPECIESSOLVER)(iPoint,0)
-
     T = Tu*(1-C) + Tf*C
 
+    #iFLOWSOLVER = SU2Driver.GetSolverIndices()['INC.FLOW']
+    #solindex = getsolvar(SU2Driver)
+    #iTEMP = solindex.get("TEMPERATURE")
+    #T = SU2Driver.Solution(iFLOWSOLVER)(iPoint,iTEMP)
+    #SU2Driver.Solution(iFLOWSOLVER).Set(iPoint,iTEMP,cp_u*T)
+
     prim_indices = SU2Driver.GetPrimitiveIndices()
     iTemp = prim_indices['TEMPERATURE']
     SU2Driver.Primitives().Set(iPoint,iTemp, T)
+    #ih = prim_indices['ENTHALPY']
+    #SU2Driver.Primitives().Set(iPoint,ih, cp_u*(T-Tref))
+        
+    iFLOWSOLVER = SU2Driver.GetSolverIndices()['INC.FLOW']
+    iENTH = 3
+    #h = 
+    SU2Driver.Solution(iFLOWSOLVER).Set(iPoint,iENTH, cp_u*(T-Tref))
+
 
 # ################################################################## #
 # Source term according to Zimont
@@ -209,11 +223,9 @@ def main():
   sys.stdout.flush()
 
   # run N iterations
-  for inner_iter in range(2):
+  for inner_iter in range(2000):
     if (rank==0):
       print("python iteration ", inner_iter)
-    driver.Preprocess(inner_iter)
-    driver.Run()
 
     Source = driver.UserDefinedSource(iSPECIESSOLVER)
 
@@ -229,6 +241,10 @@ def main():
       # set the temperature to T = c*Tf + (1-c)*Tu
       update_temperature(driver, i_node)
 
+
+    driver.Preprocess(inner_iter)
+    driver.Run()
+
     driver.Postprocess()
     driver.Update()
     # Monitor the solver and output solution to file if required.

From 8f55465b65ab9ba39b64aa2347cbc216311aa296 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Tue, 23 Dec 2025 21:38:08 +0100
Subject: [PATCH 11/37] remove temperatureInc

---
 SU2_CFD/src/variables/CIncNSVariable.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/SU2_CFD/src/variables/CIncNSVariable.cpp b/SU2_CFD/src/variables/CIncNSVariable.cpp
index 3725846d1aa8..6a335e103df4 100644
--- a/SU2_CFD/src/variables/CIncNSVariable.cpp
+++ b/SU2_CFD/src/variables/CIncNSVariable.cpp
@@ -47,7 +47,6 @@ CIncNSVariable::CIncNSVariable(su2double pressure, const su2double *velocity, su
     AuxVar.resize(nPoint,nAuxVar) = su2double(0.0);
     Grad_AuxVar.resize(nPoint,nAuxVar,nDim);
   }
-  if(!Energy) TemperatureInc = config->GetInc_Temperature_Init();
 }
 
 bool CIncNSVariable::SetPrimVar(unsigned long iPoint, su2double eddy_visc, su2double turb_ke, CFluidModel *FluidModel, const su2double *scalar) {

From b64c12db44728e28c3ccc7e11f0b347baa7d706c Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Tue, 23 Dec 2025 22:07:33 +0100
Subject: [PATCH 12/37] remove unused variable

---
 SU2_CFD/include/variables/CIncEulerVariable.hpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/SU2_CFD/include/variables/CIncEulerVariable.hpp b/SU2_CFD/include/variables/CIncEulerVariable.hpp
index 5573949ea62b..dd9821f8610d 100644
--- a/SU2_CFD/include/variables/CIncEulerVariable.hpp
+++ b/SU2_CFD/include/variables/CIncEulerVariable.hpp
@@ -72,7 +72,6 @@ class CIncEulerVariable : public CFlowVariable {
   VectorType Streamwise_Periodic_RecoveredPressure,    /*!< \brief Recovered/Physical pressure [Pa] for streamwise periodic flow. */
              Streamwise_Periodic_RecoveredTemperature; /*!< \brief Recovered/Physical temperature [K] for streamwise periodic flow. */
   su2double TemperatureLimits[2];                      /*!< \brief Temperature limits [K]. */
-  su2double TemperatureInc = 0.0;                      /*!< \brief Temperature [K] imposed when energy equation is switch off. */
  public:
   /*!
    * \brief Constructor of the class.

From 9a3fd9ebc4ee880c352dc9617100e7a81e0fa514 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Wed, 24 Dec 2025 18:37:53 +0100
Subject: [PATCH 13/37] change viscosity call

---
 SU2_CFD/src/solvers/CSpeciesSolver.cpp | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/SU2_CFD/src/solvers/CSpeciesSolver.cpp b/SU2_CFD/src/solvers/CSpeciesSolver.cpp
index e04c55ef1dc6..985b67426c46 100644
--- a/SU2_CFD/src/solvers/CSpeciesSolver.cpp
+++ b/SU2_CFD/src/solvers/CSpeciesSolver.cpp
@@ -295,7 +295,6 @@ void CSpeciesSolver::Preprocessing(CGeometry* geometry, CSolver** solver_contain
                                    bool Output) {
   SU2_OMP_SAFE_GLOBAL_ACCESS(config->SetGlobalParam(config->GetKind_Solver(), RunTime_EqSystem);)
 
-  /*--- Set the laminar mass Diffusivity for the species solver. ---*/
   SU2_OMP_FOR_STAT(omp_chunk_size)
   for (auto iPoint = 0u; iPoint < nPoint; iPoint++) {
     const su2double temperature = solver_container[FLOW_SOL]->GetNodes()->GetTemperature(iPoint);
@@ -303,16 +302,16 @@ void CSpeciesSolver::Preprocessing(CGeometry* geometry, CSolver** solver_contain
     solver_container[FLOW_SOL]->GetFluidModel()->SetMassDiffusivityModel(config);
     solver_container[FLOW_SOL]->GetFluidModel()->SetTDState_T(temperature, scalar);
     /*--- Recompute viscosity, important  to get diffusivity correct across MPI ranks. ---*/
-    const su2double viscosity =  solver_container[FLOW_SOL]->GetFluidModel()->GetLaminarViscosity();
+    nodes->SetLaminarViscosity(iPoint, solver_container[FLOW_SOL]->GetFluidModel()->GetLaminarViscosity());
+    /*--- Set the laminar mass Diffusivity for the species solver. ---*/
     for (auto iVar = 0u; iVar <= nVar; iVar++) {
       const su2double mass_diffusivity = solver_container[FLOW_SOL]->GetFluidModel()->GetMassDiffusivity(iVar);
       nodes->SetDiffusivity(iPoint, mass_diffusivity, iVar);
     }
-
   }  // iPoint
   END_SU2_OMP_FOR
 
-  /*--- Clear Residual and Jacobian. Upwind second order reconstruction and gradients ---*/
+  /*--- Clear Residual and Jacobian. Upwind second order reconstruction and gradients. ---*/
   CommonPreprocessing(geometry, config, Output);
 }
 

From ef55690e2cbb8ac6a98fbdc44826977a567790f8 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Sat, 27 Dec 2025 15:32:01 +0100
Subject: [PATCH 14/37] fix some regression

---
 TestCases/hybrid_regression.py                    |  4 ++--
 .../buoyancy_cavity/lam_buoyancy_cavity.cfg       | 15 +++++++--------
 TestCases/radiation/p1model/configp1.cfg          |  6 ++++--
 TestCases/serial_regression.py                    |  8 ++++----
 TestCases/serial_regression_AD.py                 |  4 ++--
 TestCases/tutorials.py                            | 14 +++++++-------
 TestCases/vandv.py                                |  2 +-
 7 files changed, 27 insertions(+), 26 deletions(-)

diff --git a/TestCases/hybrid_regression.py b/TestCases/hybrid_regression.py
index fc6ee002821f..b95403ebb428 100644
--- a/TestCases/hybrid_regression.py
+++ b/TestCases/hybrid_regression.py
@@ -375,7 +375,7 @@ def main():
     inc_buoyancy.cfg_dir   = "incomp_navierstokes/buoyancy_cavity"
     inc_buoyancy.cfg_file  = "lam_buoyancy_cavity.cfg"
     inc_buoyancy.test_iter = 20
-    inc_buoyancy.test_vals = [-4.432484, 0.507522, 0.000000, 0.000000]
+    inc_buoyancy.test_vals = [-4.431165, 3.504788, 0.000000, 0.000000]
     test_list.append(inc_buoyancy)
 
     # Laminar heated cylinder with polynomial fluid model
@@ -665,7 +665,7 @@ def main():
     slinc_steady.cfg_dir   = "sliding_interface/incompressible_steady"
     slinc_steady.cfg_file  = "config.cfg"
     slinc_steady.test_iter = 19
-    slinc_steady.test_vals         = [19.000000, -1.048446, -1.324274]
+    slinc_steady.test_vals         = [19.000000, -1.154873, -1.378119]
     slinc_steady.test_vals_aarch64 = [19.000000, -1.048446, -1.324274]
     slinc_steady.multizone = True
     test_list.append(slinc_steady)
diff --git a/TestCases/incomp_navierstokes/buoyancy_cavity/lam_buoyancy_cavity.cfg b/TestCases/incomp_navierstokes/buoyancy_cavity/lam_buoyancy_cavity.cfg
index 47474c4a0a74..f7d53887c85f 100644
--- a/TestCases/incomp_navierstokes/buoyancy_cavity/lam_buoyancy_cavity.cfg
+++ b/TestCases/incomp_navierstokes/buoyancy_cavity/lam_buoyancy_cavity.cfg
@@ -62,14 +62,14 @@ REF_AREA= 1.0
 MARKER_HEATFLUX= ( upper, 0.0, lower, 0.0 )
 MARKER_ISOTHERMAL= ( left, 461.04, right, 115.26 )
 MARKER_PLOTTING= ( upper, left, right, lower )
-MARKER_MONITORING= ( NONE )
+MARKER_MONITORING= ( left, right,upper )
 
 % ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------%
 %
 NUM_METHOD_GRAD= GREEN_GAUSS
-CFL_NUMBER= 1e2
-CFL_ADAPT= NO
-CFL_ADAPT_PARAM= ( 1.5, 0.5, 15.0, 1e10)
+CFL_NUMBER= 20
+CFL_ADAPT= YES
+CFL_ADAPT_PARAM= ( 0.95, 1.01, 10, 1000, 0.001, 0)
 MAX_DELTA_TIME= 1E6
 RK_ALPHA_COEFF= ( 0.66667, 0.66667, 1.000000 )
 ITER= 99999
@@ -79,8 +79,8 @@ ITER= 99999
 LINEAR_SOLVER= FGMRES
 LINEAR_SOLVER_PREC= ILU
 LINEAR_SOLVER_ILU_FILL_IN= 0
-LINEAR_SOLVER_ERROR= 1E-15
-LINEAR_SOLVER_ITER= 20
+LINEAR_SOLVER_ERROR= 1E-06
+LINEAR_SOLVER_ITER= 25
 
 % -------------------- FLOW NUMERICAL METHOD DEFINITION -----------------------%
 %
@@ -114,7 +114,6 @@ GRAD_OBJFUNC_FILENAME= of_grad
 SURFACE_FILENAME= surface_flow
 SURFACE_ADJ_FILENAME= surface_adjoint
 OUTPUT_WRT_FREQ= 100
-SCREEN_OUTPUT= (INNER_ITER, RMS_PRESSURE, RMS_ENTHALPY, LIFT, DRAG)
-
+SCREEN_OUTPUT= (INNER_ITER, RMS_PRESSURE, RMS_VELOCITY-X, RMS_ENTHALPY, TOTAL_HEATFLUX)
 % ----------------------- GEOMETRY EVALUATION PARAMETERS ----------------------%
 GEO_BOUNDS= ( 0.499, 0.501)
diff --git a/TestCases/radiation/p1model/configp1.cfg b/TestCases/radiation/p1model/configp1.cfg
index 6c779b16d0fb..be5787656d31 100644
--- a/TestCases/radiation/p1model/configp1.cfg
+++ b/TestCases/radiation/p1model/configp1.cfg
@@ -67,7 +67,7 @@ MARKER_MONITORING= ( upper, left )
 LINEAR_SOLVER= FGMRES
 LINEAR_SOLVER_PREC= ILU
 LINEAR_SOLVER_ILU_FILL_IN= 0
-LINEAR_SOLVER_ERROR= 1E-8
+LINEAR_SOLVER_ERROR= 1E-6
 LINEAR_SOLVER_ITER= 10
 
 %%%%%%%%%%%%%%%%%%%%%%%
@@ -80,12 +80,14 @@ MUSCL_FLOW= YES
 SLOPE_LIMITER_FLOW= NONE
 TIME_DISCRE_FLOW= EULER_IMPLICIT
 CFL_NUMBER= 100
+CFL_ADAPT= YES
+CFL_ADAPT_PARAM= ( 0.9, 1.10, 100.0, 1000, 0.1, 0)
 
 %%%%%%%%%%%%%%%%%%%%%%%
 % CONVERGENCE CRITERIA
 %%%%%%%%%%%%%%%%%%%%%%%
 
-INNER_ITER= 101
+INNER_ITER= 51
 
 CONV_RESIDUAL_MINVAL= -10
 CONV_STARTITER= 10
diff --git a/TestCases/serial_regression.py b/TestCases/serial_regression.py
index cfd25784fa03..9c88fb838851 100755
--- a/TestCases/serial_regression.py
+++ b/TestCases/serial_regression.py
@@ -458,7 +458,7 @@ def main():
     inc_turb_wallfunction_flatplate_sst.cfg_dir   = "wallfunctions/flatplate/incompressible_SST"
     inc_turb_wallfunction_flatplate_sst.cfg_file  = "turb_SST_flatplate.cfg"
     inc_turb_wallfunction_flatplate_sst.test_iter = 10
-    inc_turb_wallfunction_flatplate_sst.test_vals = [-6.881656, -5.732047, -6.724784, -4.242639, -7.189741, -2.050900, 10.000000, -2.877778, 0.001149, 0.003172, 0.000000]
+    inc_turb_wallfunction_flatplate_sst.test_vals = [-6.881887, -5.731983, -6.725181, -2.618754, -7.189701, -2.050891, 10.000000, -2.027265, 0.001155, 0.003172, 0.000000]
     test_list.append(inc_turb_wallfunction_flatplate_sst)
 
     # FLAT PLATE, WALL FUNCTIONS, INCOMPRESSIBLE SA
@@ -466,7 +466,7 @@ def main():
     inc_turb_wallfunction_flatplate_sa.cfg_dir   = "wallfunctions/flatplate/incompressible_SA"
     inc_turb_wallfunction_flatplate_sa.cfg_file  = "turb_SA_flatplate.cfg"
     inc_turb_wallfunction_flatplate_sa.test_iter = 10
-    inc_turb_wallfunction_flatplate_sa.test_vals = [-6.894226, -5.716031, -6.743814, -4.242551, -9.550079, 10.000000, -2.879412, 0.001021, 0.003759]
+    inc_turb_wallfunction_flatplate_sa.test_vals = [-6.894473, -5.715971, -6.744286, -2.631311, -9.550134, 10.000000, -2.017104, 0.001027, 0.003759]
     test_list.append(inc_turb_wallfunction_flatplate_sa)
 
     ####################
@@ -986,7 +986,7 @@ def main():
     slinc_steady.cfg_dir   = "sliding_interface/incompressible_steady"
     slinc_steady.cfg_file  = "config.cfg"
     slinc_steady.test_iter = 19
-    slinc_steady.test_vals = [19.000000, -1.049468, -1.303013]
+    slinc_steady.test_vals = [19.000000, -1.148249, -1.398402]
     slinc_steady.timeout   = 100
     slinc_steady.multizone = True
     test_list.append(slinc_steady)
@@ -1097,7 +1097,7 @@ def main():
     p1rad           = TestCase('p1rad')
     p1rad.cfg_dir   = "radiation/p1model"
     p1rad.cfg_file  = "configp1.cfg"
-    p1rad.test_iter = 100
+    p1rad.test_iter = 50
     p1rad.test_vals = [-7.751309, -7.923059, -2.119084, 0.091733, -47.387000]
     test_list.append(p1rad)
 
diff --git a/TestCases/serial_regression_AD.py b/TestCases/serial_regression_AD.py
index 0cb1b5715891..4bffc9ec0aa7 100644
--- a/TestCases/serial_regression_AD.py
+++ b/TestCases/serial_regression_AD.py
@@ -194,7 +194,7 @@ def main():
     discadj_heat.cfg_dir   = "disc_adj_heat"
     discadj_heat.cfg_file  = "disc_adj_heat.cfg"
     discadj_heat.test_iter = 10
-    discadj_heat.test_vals = [-2.685957, 0.665986, 0.000000, -9.155800]
+    discadj_heat.test_vals = [-2.677870, 0.674825, 0.000000, -9.215500]
     test_list.append(discadj_heat)
 
     ###################################
@@ -219,7 +219,7 @@ def main():
     discadj_cht.cfg_dir   = "coupled_cht/disc_adj_incomp_2d"
     discadj_cht.cfg_file  = "cht_2d_3cylinders.cfg"
     discadj_cht.test_iter = 10
-    discadj_cht.test_vals = [-6.131112, -2.564634, -2.565220, -2.565304]
+    discadj_cht.test_vals = [-6.308199, -3.086023, -3.086024, -3.086024]
     test_list.append(discadj_cht)
 
     ######################################
diff --git a/TestCases/tutorials.py b/TestCases/tutorials.py
index 0768bc29370d..eccb5f3e630c 100644
--- a/TestCases/tutorials.py
+++ b/TestCases/tutorials.py
@@ -49,7 +49,7 @@ def main():
     cht_incompressible_unsteady.cfg_dir   = "../Tutorials/multiphysics/unsteady_cht/"
     cht_incompressible_unsteady.cfg_file  = "cht_2d_3cylinders.cfg"
     cht_incompressible_unsteady.test_iter = 2
-    cht_incompressible_unsteady.test_vals = [-2.661440, -2.534489, -0.080399, -0.080399, -0.080399, -12.421979, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 238.240000] #last columns
+    cht_incompressible_unsteady.test_vals = [-1.742894, -3.075372, -0.080399, -0.080399, -0.080399, -11.163219, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 238.240000] #last columns
     cht_incompressible_unsteady.multizone = True
     cht_incompressible_unsteady.unsteady  = True
     test_list.append(cht_incompressible_unsteady)
@@ -69,7 +69,7 @@ def main():
     cht_CR.cfg_dir   = "../Tutorials/multiphysics/contact_resistance_cht"
     cht_CR.cfg_file  = "master.cfg"
     cht_CR.test_iter = 80
-    cht_CR.test_vals = [-8.606916, -9.227614, -10.411674, -2.116659]
+    cht_CR.test_vals = [-8.606938, -9.227901, -10.410107, -2.129377]
     cht_CR.multizone = True
     test_list.append(cht_CR)
 
@@ -80,7 +80,7 @@ def main():
     sp_pinArray_2d_mf_hf.cfg_dir   = "../Tutorials/incompressible_flow/Inc_Streamwise_Periodic"
     sp_pinArray_2d_mf_hf.cfg_file  = "sp_pinArray_2d_mf_hf.cfg"
     sp_pinArray_2d_mf_hf.test_iter = 25
-    sp_pinArray_2d_mf_hf.test_vals = [-4.685131, 1.388616, -0.755475, 241.878084]
+    sp_pinArray_2d_mf_hf.test_vals = [-4.684477, 0.844369, -0.755565, 241.872175]
     sp_pinArray_2d_mf_hf.test_vals_aarch64 = [-4.686092, 1.387918, -0.755447, 241.878841]
     test_list.append(sp_pinArray_2d_mf_hf)
 
@@ -89,7 +89,7 @@ def main():
     sp_pinArray_2d_dp_hf_tp.cfg_dir   = "../Tutorials/incompressible_flow/Inc_Streamwise_Periodic"
     sp_pinArray_2d_dp_hf_tp.cfg_file  = "sp_pinArray_2d_dp_hf_tp.cfg"
     sp_pinArray_2d_dp_hf_tp.test_iter = 25
-    sp_pinArray_2d_dp_hf_tp.test_vals = [-4.737196, 1.322378, -0.713373, 208.023676]
+    sp_pinArray_2d_dp_hf_tp.test_vals = [-4.739886, 0.520841, -0.713547, 208.023676]
     sp_pinArray_2d_dp_hf_tp.test_vals_aarch64 = [-4.733643, 1.325195, -0.713411, 208.023676]
     test_list.append(sp_pinArray_2d_dp_hf_tp)
 
@@ -136,7 +136,7 @@ def main():
     species3_primitiveVenturi.cfg_dir   = "../Tutorials/incompressible_flow/Inc_Species_Transport"
     species3_primitiveVenturi.cfg_file  = "species3_primitiveVenturi.cfg"
     species3_primitiveVenturi.test_iter = 50
-    species3_primitiveVenturi.test_vals = [-5.673008, -4.673131, -4.692722, -5.445021, -1.069687, -5.960203, -6.065022, 5.000000, -0.570021, 5.000000, -2.512831, 5.000000, -0.525792, 1.660602, 0.502278, 0.603347, 0.554978]
+    species3_primitiveVenturi.test_vals = [-5.673011, -4.673114, -4.692686, -5.445043, -1.069650, -5.960206, -6.065010, 5.000000, -0.569992, 5.000000, -2.512966, 5.000000, -0.525813, 1.660601, 0.502277, 0.603346, 0.554977]
     test_list.append(species3_primitiveVenturi)
 
     # 3 species (2 eq) primitive venturi mixing
@@ -144,7 +144,7 @@ def main():
     DAspecies3_primitiveVenturi.cfg_dir   = "../Tutorials/incompressible_flow/Inc_Species_Transport"
     DAspecies3_primitiveVenturi.cfg_file  = "DAspecies3_primitiveVenturi.cfg"
     DAspecies3_primitiveVenturi.test_iter = 50
-    DAspecies3_primitiveVenturi.test_vals = [-9.819097, -8.643457, -8.676919, -8.347340, -12.926241, -9.739487, -8.947991]
+    DAspecies3_primitiveVenturi.test_vals = [-9.821887, -8.644118, -8.677534, -8.347228, -12.926295, -9.739487, -8.947991]
     DAspecies3_primitiveVenturi.command   = TestCase.Command("mpirun -n 2", "SU2_CFD_AD")
     test_list.append(DAspecies3_primitiveVenturi)
 
@@ -153,7 +153,7 @@ def main():
     kenics_mixer_tutorial.cfg_dir   = "../Tutorials/incompressible_flow/Inc_Species_Transport_Composition_Dependent_Model"
     kenics_mixer_tutorial.cfg_file  = "kenics_mixer_tutorial.cfg"
     kenics_mixer_tutorial.test_iter = 10
-    kenics_mixer_tutorial.test_vals = [-7.490303, -6.823796, -6.838369, -6.383332, -7.907780, -3.062276, -7.451176, 5.000000, -1.858354, 4.000000, -5.318193, 3.000000, -6.371744, 0.025671, 0.000000, 0.025671, 0.000000, 62.846000, 8.470600, 46.847000, 7.527900]
+    kenics_mixer_tutorial.test_vals = [-7.490472, -6.823803, -6.838373, -6.383764, -7.907928, -3.062404, -7.452184, 5.000000, -1.858094, 4.000000, -5.318066, 3.000000, -6.371967, 0.025661, 0.000000, 0.025661, 0.000000, 62.736000, 8.470600, 46.738000, 7.527900]
     kenics_mixer_tutorial.command   = TestCase.Command("mpirun -n 2", "SU2_CFD")
     test_list.append(kenics_mixer_tutorial)
 
diff --git a/TestCases/vandv.py b/TestCases/vandv.py
index f7b197632ca4..a379e775c0f0 100644
--- a/TestCases/vandv.py
+++ b/TestCases/vandv.py
@@ -111,7 +111,7 @@ def main():
     sandiajet_sst.cfg_dir   = "vandv/species_transport/sandia_jet"
     sandiajet_sst.cfg_file  = "validation.cfg"
     sandiajet_sst.test_iter = 5
-    sandiajet_sst.test_vals = [-8.271400, -6.305945, -6.123143, -5.634565, -1.687556, -7.869775, 5.000000, -1.527449, 5.000000, -4.053788, 5.000000, -2.303502, 0.000257, 0.000000, 0.000000, 0.000257, 4020.500000, 3919.900000, 49.151000, 51.436000]
+    sandiajet_sst.test_vals = [-4.930056, -3.072757, -3.531917, -3.632319, 1.186060, -6.175518, 5.000000, -1.413277, 5.000000, -4.735257, 5.000000, -1.924560, 0.000256, 0.000000, 0.000000, 0.000256, 4126.200000, 4008.100000, 62.399000, 55.713000]
     sandiajet_sst.test_vals_aarch64 = [-8.271400, -6.305945, -6.123143, -5.634565, -1.687556, -7.869775, 5.000000, -1.527449, 5.000000, -4.053788, 5.000000, -2.303502, 0.000257, 0.000000, 0.000000, 0.000257, 4020.500000, 3919.900000, 49.151000, 51.436000]
     test_list.append(sandiajet_sst)
 

From eaf54d623e2136d8836194e077479d60a15e1f71 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Sat, 27 Dec 2025 21:47:12 +0100
Subject: [PATCH 15/37] fix some regression

---
 TestCases/hybrid_regression.py                     |  2 +-
 TestCases/parallel_regression.py                   | 12 ++++++------
 TestCases/py_wrapper/turbulent_premixed_psi/run.py |  2 +-
 TestCases/serial_regression.py                     |  4 ++--
 4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/TestCases/hybrid_regression.py b/TestCases/hybrid_regression.py
index b95403ebb428..5b1642e92f35 100644
--- a/TestCases/hybrid_regression.py
+++ b/TestCases/hybrid_regression.py
@@ -375,7 +375,7 @@ def main():
     inc_buoyancy.cfg_dir   = "incomp_navierstokes/buoyancy_cavity"
     inc_buoyancy.cfg_file  = "lam_buoyancy_cavity.cfg"
     inc_buoyancy.test_iter = 20
-    inc_buoyancy.test_vals = [-4.431165, 3.504788, 0.000000, 0.000000]
+    inc_buoyancy.test_vals = [-3.860456, -3.122396, 4.074516, -23.415000]
     test_list.append(inc_buoyancy)
 
     # Laminar heated cylinder with polynomial fluid model
diff --git a/TestCases/parallel_regression.py b/TestCases/parallel_regression.py
index 9227d447d597..643649b7af55 100755
--- a/TestCases/parallel_regression.py
+++ b/TestCases/parallel_regression.py
@@ -603,7 +603,7 @@ def main():
     inc_buoyancy.cfg_dir   = "incomp_navierstokes/buoyancy_cavity"
     inc_buoyancy.cfg_file  = "lam_buoyancy_cavity.cfg"
     inc_buoyancy.test_iter = 20
-    inc_buoyancy.test_vals = [-4.435827, 0.508037, 0.000000, 0.000000]
+    inc_buoyancy.test_vals = [-3.860462, -3.122401, 4.074510, -23.414000]
     test_list.append(inc_buoyancy)
 
     # Laminar heated cylinder with polynomial fluid model
@@ -635,7 +635,7 @@ def main():
     inc_heatTransfer_BC.cfg_dir   = "incomp_navierstokes/streamwise_periodic/chtPinArray_2d"
     inc_heatTransfer_BC.cfg_file  = "BC_HeatTransfer.cfg"
     inc_heatTransfer_BC.test_iter = 50
-    inc_heatTransfer_BC.test_vals = [-8.747445, -7.653823, -8.079512, -0.654920, -1670.100000]
+    inc_heatTransfer_BC.test_vals = [-8.686723, -7.601245, -8.072766, 1.864213, -1669.800000]
     test_list.append(inc_heatTransfer_BC)
 
     ############################
@@ -1209,7 +1209,7 @@ def main():
     slinc_steady.cfg_dir   = "sliding_interface/incompressible_steady"
     slinc_steady.cfg_file  = "config.cfg"
     slinc_steady.test_iter = 19
-    slinc_steady.test_vals = [19.000000, -1.012869, -1.222087]
+    slinc_steady.test_vals = [19.000000, -1.131557, -1.370471]
     slinc_steady.timeout   = 100
     slinc_steady.tol       = 0.00002
     slinc_steady.multizone = True
@@ -1318,7 +1318,7 @@ def main():
     p1rad           = TestCase('p1rad')
     p1rad.cfg_dir   = "radiation/p1model"
     p1rad.cfg_file  = "configp1.cfg"
-    p1rad.test_iter = 100
+    p1rad.test_iter = 50
     p1rad.test_vals = [-7.743666, -7.921411, -2.111848, 0.098302, -47.897000]
     test_list.append(p1rad)
 
@@ -1363,7 +1363,7 @@ def main():
     sp_pinArray_cht_2d_dp_hf.cfg_dir   = "incomp_navierstokes/streamwise_periodic/chtPinArray_2d"
     sp_pinArray_cht_2d_dp_hf.cfg_file  = "configMaster.cfg"
     sp_pinArray_cht_2d_dp_hf.test_iter = 100
-    sp_pinArray_cht_2d_dp_hf.test_vals = [0.379544, 2.491817, -1.255558, -0.613405, 208.023676, 349.870000, -0.000000, -0.613410, 0.613410]
+    sp_pinArray_cht_2d_dp_hf.test_vals = [0.353740, 2.436726, -1.270003, -0.615079, 208.023676, 350.100000, -0.000000, -0.615080, 0.615080]
     sp_pinArray_cht_2d_dp_hf.multizone = True
     test_list.append(sp_pinArray_cht_2d_dp_hf)
 
@@ -1372,7 +1372,7 @@ def main():
     sp_pinArray_3d_cht_mf_hf_tp.cfg_dir   = "incomp_navierstokes/streamwise_periodic/chtPinArray_3d"
     sp_pinArray_3d_cht_mf_hf_tp.cfg_file  = "configMaster.cfg"
     sp_pinArray_3d_cht_mf_hf_tp.test_iter = 30
-    sp_pinArray_3d_cht_mf_hf_tp.test_vals = [0.261726, 3.878700, 0.298987, -0.009537, 104.749181, 354.800000, 0.000000]
+    sp_pinArray_3d_cht_mf_hf_tp.test_vals = [-1.279608, 3.011923, -0.641797, -0.009777, 104.609505, 410.330000, 0.000000]
     sp_pinArray_3d_cht_mf_hf_tp.multizone = True
     test_list.append(sp_pinArray_3d_cht_mf_hf_tp)
 
diff --git a/TestCases/py_wrapper/turbulent_premixed_psi/run.py b/TestCases/py_wrapper/turbulent_premixed_psi/run.py
index 8097c8b08fa1..1f355f135e6f 100644
--- a/TestCases/py_wrapper/turbulent_premixed_psi/run.py
+++ b/TestCases/py_wrapper/turbulent_premixed_psi/run.py
@@ -223,7 +223,7 @@ def main():
   sys.stdout.flush()
 
   # run N iterations
-  for inner_iter in range(2000):
+  for inner_iter in range(10):
     if (rank==0):
       print("python iteration ", inner_iter)
 
diff --git a/TestCases/serial_regression.py b/TestCases/serial_regression.py
index 9c88fb838851..8dd870bfd7ba 100755
--- a/TestCases/serial_regression.py
+++ b/TestCases/serial_regression.py
@@ -407,7 +407,7 @@ def main():
     inc_buoyancy.cfg_dir   = "incomp_navierstokes/buoyancy_cavity"
     inc_buoyancy.cfg_file  = "lam_buoyancy_cavity.cfg"
     inc_buoyancy.test_iter = 20
-    inc_buoyancy.test_vals = [-4.436657, 0.507847, 0.000000, 0.000000]
+    inc_buoyancy.test_vals = [-3.860463, -3.122402, 4.074509, -23.414000]
     test_list.append(inc_buoyancy)
 
     # Laminar heated cylinder with polynomial fluid model
@@ -1098,7 +1098,7 @@ def main():
     p1rad.cfg_dir   = "radiation/p1model"
     p1rad.cfg_file  = "configp1.cfg"
     p1rad.test_iter = 50
-    p1rad.test_vals = [-7.751309, -7.923059, -2.119084, 0.091733, -47.387000]
+    p1rad.test_vals = [-8.284673, -8.008659, -2.424204, 0.389030, -56.560000]
     test_list.append(p1rad)
 
     # ###############################

From 38cfefbd477743e8a08c5c2646ce387d736f2c89 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Mon, 29 Dec 2025 12:59:00 +0100
Subject: [PATCH 16/37] nondimensionalize poly-cp

---
 SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp b/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
index aff8085617d9..f14b69d92e3c 100644
--- a/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
+++ b/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
@@ -61,7 +61,7 @@ class CIncIdealGasPolynomial final : public CFluidModel {
     Enthalpy_Ref = 0.0;
     su2double t_i = 1.0;
     for (int i = 0; i < N; ++i) {
-      t_i *= STD_REF_TEMP;
+      t_i *= STD_REF_TEMP / config->GetInc_Temperature_Ref();
       coeffs_[i] = config->GetCp_PolyCoeffND(i);
       Enthalpy_Ref += coeffs_[i] * t_i / (i + 1);
     }

From bcfe6227bf3a922f8ea9ba9749a0a8eaee194082 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Mon, 29 Dec 2025 23:27:55 +0100
Subject: [PATCH 17/37] change nondimensionalization of cp and enthalpy

---
 .github/workflows/regression.yml              |  2 +-
 SU2_CFD/include/fluid/CConstantDensity.hpp    | 10 ++++++---
 SU2_CFD/include/fluid/CFluidModel.hpp         |  4 ++--
 SU2_CFD/include/fluid/CIncIdealGas.hpp        |  8 ++++---
 .../include/fluid/CIncIdealGasPolynomial.hpp  | 16 +++++++++-----
 SU2_CFD/src/solvers/CIncEulerSolver.cpp       | 16 +++++++-------
 SU2_CFD/src/solvers/CSolver.cpp               |  2 --
 .../cylinder/heated_cylinder.cfg              |  2 +-
 .../lam_prem_ch4_cfd.cfg                      | 17 ++++++++-------
 .../lam_prem_ch4_cfd_axi.cfg                  | 21 +++++++++++--------
 TestCases/hybrid_regression.py                |  2 +-
 11 files changed, 58 insertions(+), 42 deletions(-)

diff --git a/.github/workflows/regression.yml b/.github/workflows/regression.yml
index b7d4c3530d01..6bddf426aab7 100644
--- a/.github/workflows/regression.yml
+++ b/.github/workflows/regression.yml
@@ -211,7 +211,7 @@ jobs:
         uses: docker://ghcr.io/su2code/su2/test-su2:250717-1402
         with:
           # -t <Tutorials-branch> -c <Testcases-branch>
-          args: -b ${{github.ref}} -t develop -c develop -s ${{matrix.testscript}}
+          args: -b ${{github.ref}} -t develop -c fix_enthalpy -s ${{matrix.testscript}}
       - name: Cleanup
         uses: docker://ghcr.io/su2code/su2/test-su2:250717-1402
         with:
diff --git a/SU2_CFD/include/fluid/CConstantDensity.hpp b/SU2_CFD/include/fluid/CConstantDensity.hpp
index a796762a2713..4ba06242add7 100644
--- a/SU2_CFD/include/fluid/CConstantDensity.hpp
+++ b/SU2_CFD/include/fluid/CConstantDensity.hpp
@@ -39,10 +39,11 @@ class CConstantDensity final : public CFluidModel {
   /*!
    * \brief Constructor of the class.
    */
-  CConstantDensity(su2double val_Density, su2double val_Cp) {
+  CConstantDensity(su2double val_Density, su2double val_Cp, su2double val_Temperature_Ref) {
     Density = val_Density;
     Cp = val_Cp;
     Cv = val_Cp;
+    Std_Ref_Temp_ND = val_Temperature_Ref;
   }
 
   /*!
@@ -56,7 +57,7 @@ class CConstantDensity final : public CFluidModel {
        decoupled equation. Hence, we update the value.
        Note Cp = Cv, (gamma = 1).*/
     Temperature = t;
-    Enthalpy = Cp * (Temperature - STD_REF_TEMP);  // Sensible enthalpy relative to STD_REF_TEMP
+    Enthalpy = Cp * (Temperature - Std_Ref_Temp_ND);  // Sensible enthalpy relative to STD_REF_TEMP
   }
 
   /*!
@@ -66,6 +67,9 @@ class CConstantDensity final : public CFluidModel {
    */
   void SetTDState_h(su2double val_enthalpy, const su2double* val_scalars = nullptr) override {
     Enthalpy = val_enthalpy;
-    Temperature = Enthalpy / Cp + STD_REF_TEMP;  // Temperature from sensible enthalpy
+    Temperature = Enthalpy / Cp + Std_Ref_Temp_ND;  // Temperature from sensible enthalpy
   }
+
+ private:
+  su2double Std_Ref_Temp_ND{0.0}; /*!< \brief Nondimensional standard reference temperature for enthalpy. */
 };
diff --git a/SU2_CFD/include/fluid/CFluidModel.hpp b/SU2_CFD/include/fluid/CFluidModel.hpp
index 03f1e7d66052..2b774296fd56 100644
--- a/SU2_CFD/include/fluid/CFluidModel.hpp
+++ b/SU2_CFD/include/fluid/CFluidModel.hpp
@@ -279,7 +279,7 @@ class CFluidModel {
   /*!
    * \brief Set specific heat Cp model.
    */
-  virtual void SetCpModel(const CConfig* config) {}
+  virtual void SetCpModel(const CConfig* config, su2double val_Temperature_Ref) {}
 
   /*!
    * \brief Set viscosity model.
@@ -372,7 +372,7 @@ class CFluidModel {
   /*!
    * \brief Virtual member.
    * \param[in] val_enthalpy - Enthalpy value at the point.
-   * \param[in] val_scalars - Scalar mass fractions. 
+   * \param[in] val_scalars - Scalar mass fractions.
    */
   virtual void SetTDState_h(su2double val_enthalpy, const su2double* val_scalars = nullptr) {}
 
diff --git a/SU2_CFD/include/fluid/CIncIdealGas.hpp b/SU2_CFD/include/fluid/CIncIdealGas.hpp
index 4b35735f096d..a45a61392db2 100644
--- a/SU2_CFD/include/fluid/CIncIdealGas.hpp
+++ b/SU2_CFD/include/fluid/CIncIdealGas.hpp
@@ -39,7 +39,7 @@ class CIncIdealGas final : public CFluidModel {
   /*!
    * \brief Constructor of the class.
    */
-  CIncIdealGas(su2double val_Cp, su2double val_gas_constant, su2double val_operating_pressure) {
+  CIncIdealGas(su2double val_Cp, su2double val_gas_constant, su2double val_operating_pressure, su2double val_Temperature_Ref) {
     /*--- In the incompressible ideal gas model, the thermodynamic pressure
   is decoupled from the governing equations and held constant. The
   density is therefore only a function of temperature variations. ---*/
@@ -48,6 +48,7 @@ class CIncIdealGas final : public CFluidModel {
     Gamma = 1.0;
     Cp = val_Cp;
     Cv = Cp;
+    Std_Ref_Temp_ND = STD_REF_TEMP / val_Temperature_Ref;
   }
 
   /*!
@@ -58,7 +59,7 @@ class CIncIdealGas final : public CFluidModel {
     /*--- The EoS only depends upon temperature. ---*/
     Temperature = t;
     Density = Pressure / (Temperature * Gas_Constant);
-    Enthalpy = Cp * (Temperature - STD_REF_TEMP);  // Sensible enthalpy relative to REF_TEMP
+    Enthalpy = Cp * (Temperature - Std_Ref_Temp_ND);  // Sensible enthalpy relative to REF_TEMP
   }
 
   /*!
@@ -67,11 +68,12 @@ class CIncIdealGas final : public CFluidModel {
    */
   void SetTDState_h(su2double val_enthalpy, const su2double* val_scalars = nullptr) override {
     Enthalpy = val_enthalpy;
-    Temperature = Enthalpy / Cp + STD_REF_TEMP;  // Temperature from sensible enthalpy
+    Temperature = Enthalpy / Cp + Std_Ref_Temp_ND;  // Temperature from sensible enthalpy
     Density = Pressure / (Temperature * Gas_Constant);
   }
 
  private:
   su2double Gas_Constant{0.0}; /*!< \brief Gas Constant. */
   su2double Gamma{0.0};        /*!< \brief Heat Capacity Ratio. */
+  su2double Std_Ref_Temp_ND{0.0}; /*!< \brief Nondimensional standard reference temperature for enthalpy. */
 };
diff --git a/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp b/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
index f14b69d92e3c..efba9fd3d4ed 100644
--- a/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
+++ b/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
@@ -42,7 +42,7 @@ class CIncIdealGasPolynomial final : public CFluidModel {
   /*!
    * \brief Constructor of the class.
    */
-  CIncIdealGasPolynomial(su2double val_gas_constant, su2double val_operating_pressure) {
+  CIncIdealGasPolynomial(su2double val_gas_constant, su2double val_operating_pressure, su2double val_Temperature_Ref) {
     /* In the incompressible ideal gas model, the thermodynamic pressure is decoupled
     from the governing equations and held constant. The density is therefore only a
     function of temperature variations. We also use a molecular weight (g/mol) and the
@@ -51,17 +51,20 @@ class CIncIdealGasPolynomial final : public CFluidModel {
     Gas_Constant = val_gas_constant;
     Pressure = val_operating_pressure;
     Gamma = 1.0;
+    Std_Ref_Temp_ND = val_Temperature_Ref;
   }
 
   /*!
    * \brief Set the temperature polynomial coefficients for variable Cp.
    * \param[in] config - configuration container for the problem.
    */
-  void SetCpModel(const CConfig* config) override {
+  void SetCpModel(const CConfig* config, su2double val_Temperature_Ref) override {
+    const su2double t_ref = val_Temperature_Ref;
     Enthalpy_Ref = 0.0;
     su2double t_i = 1.0;
     for (int i = 0; i < N; ++i) {
-      t_i *= STD_REF_TEMP / config->GetInc_Temperature_Ref();
+      /*--- Note that we use cp = dh/dt here. ---*/
+      t_i *= t_ref - Std_Ref_Temp_ND;
       coeffs_[i] = config->GetCp_PolyCoeffND(i);
       Enthalpy_Ref += coeffs_[i] * t_i / (i + 1);
     }
@@ -79,12 +82,14 @@ class CIncIdealGasPolynomial final : public CFluidModel {
 
     /* Evaluate the new Cp and enthalpy from the coefficients and temperature. */
     Cp = coeffs_[0];
-    Enthalpy = coeffs_[0] * t - Enthalpy_Ref;
+    su2double tref_i = t - Std_Ref_Temp_ND;
+    Enthalpy = coeffs_[0] * tref_i;
     su2double t_i = 1.0;
     for (int i = 1; i < N; ++i) {
       t_i *= t;
+      tref_i *= (t - Std_Ref_Temp_ND);
       Cp += coeffs_[i] * t_i;
-      Enthalpy += coeffs_[i] * t_i * t / (i + 1);
+      Enthalpy += coeffs_[i] * tref_i / (i + 1);
     }
     Cv = Cp / Gamma;
   }
@@ -140,6 +145,7 @@ class CIncIdealGasPolynomial final : public CFluidModel {
  private:
   su2double Gas_Constant{0.0}; /*!< \brief Specific Gas Constant. */
   su2double Gamma{0.0};        /*!< \brief Ratio of specific heats. */
+  su2double Std_Ref_Temp_ND{0.0}; /*!< \brief Nondimensional standard reference temperature for enthalpy. */
   array<su2double, N> coeffs_; /*!< \brief Polynomial coefficients for heat capacity as a function of temperature. */
   su2double Enthalpy_Ref;      /*!< \brief Enthalpy computed at the reference temperature. */
   su2double Temperature_Min;   /*!< \brief Minimum temperature value allowed in Newton-Raphson iterations. */
diff --git a/SU2_CFD/src/solvers/CIncEulerSolver.cpp b/SU2_CFD/src/solvers/CIncEulerSolver.cpp
index bee02216dd83..cfb49fb9ff55 100644
--- a/SU2_CFD/src/solvers/CIncEulerSolver.cpp
+++ b/SU2_CFD/src/solvers/CIncEulerSolver.cpp
@@ -289,7 +289,7 @@ void CIncEulerSolver::SetNondimensionalization(CConfig *config, unsigned short i
 
     case CONSTANT_DENSITY:
 
-      auxFluidModel = new CConstantDensity(Density_FreeStream, config->GetSpecific_Heat_Cp());
+      auxFluidModel = new CConstantDensity(Density_FreeStream, config->GetSpecific_Heat_Cp(), Temperature_FreeStream);
       auxFluidModel->SetTDState_T(Temperature_FreeStream);
       break;
 
@@ -297,7 +297,7 @@ void CIncEulerSolver::SetNondimensionalization(CConfig *config, unsigned short i
 
       config->SetGas_Constant(UNIVERSAL_GAS_CONSTANT/(config->GetMolecular_Weight()/1000.0));
       Pressure_Thermodynamic = Density_FreeStream*Temperature_FreeStream*config->GetGas_Constant();
-      auxFluidModel = new CIncIdealGas(config->GetSpecific_Heat_Cp(), config->GetGas_Constant(), Pressure_Thermodynamic);
+      auxFluidModel = new CIncIdealGas(config->GetSpecific_Heat_Cp(), config->GetGas_Constant(), Pressure_Thermodynamic, Temperature_FreeStream);
       auxFluidModel->SetTDState_T(Temperature_FreeStream);
       Pressure_Thermodynamic = auxFluidModel->GetPressure();
       config->SetPressure_Thermodynamic(Pressure_Thermodynamic);
@@ -307,12 +307,12 @@ void CIncEulerSolver::SetNondimensionalization(CConfig *config, unsigned short i
 
       config->SetGas_Constant(UNIVERSAL_GAS_CONSTANT/(config->GetMolecular_Weight()/1000.0));
       Pressure_Thermodynamic = Density_FreeStream*Temperature_FreeStream*config->GetGas_Constant();
-      auxFluidModel = new CIncIdealGasPolynomial<N_POLY_COEFFS>(config->GetGas_Constant(), Pressure_Thermodynamic);
+      auxFluidModel = new CIncIdealGasPolynomial<N_POLY_COEFFS>(config->GetGas_Constant(), Pressure_Thermodynamic, Temperature_FreeStream);
       if (viscous) {
         /*--- Variable Cp model via polynomial. ---*/
         for (iVar = 0; iVar < config->GetnPolyCoeffs(); iVar++)
           config->SetCp_PolyCoeffND(config->GetCp_PolyCoeff(iVar), iVar);
-        auxFluidModel->SetCpModel(config);
+        auxFluidModel->SetCpModel(config, Temperature_FreeStream);
       }
       auxFluidModel->SetTDState_T(Temperature_FreeStream);
       Pressure_Thermodynamic = auxFluidModel->GetPressure();
@@ -480,11 +480,11 @@ void CIncEulerSolver::SetNondimensionalization(CConfig *config, unsigned short i
     switch (config->GetKind_FluidModel()) {
 
       case CONSTANT_DENSITY:
-        fluidModel = new CConstantDensity(Density_FreeStreamND, Specific_Heat_CpND);
+        fluidModel = new CConstantDensity(Density_FreeStreamND, Specific_Heat_CpND, STD_REF_TEMP / config->GetTemperature_Ref());
         break;
 
       case INC_IDEAL_GAS:
-        fluidModel = new CIncIdealGas(Specific_Heat_CpND, Gas_ConstantND, Pressure_ThermodynamicND);
+        fluidModel = new CIncIdealGas(Specific_Heat_CpND, Gas_ConstantND, Pressure_ThermodynamicND, Temperature_FreeStreamND);
         fluidModel->SetTDState_T(Temperature_FreeStreamND);
         break;
 
@@ -499,13 +499,13 @@ void CIncEulerSolver::SetNondimensionalization(CConfig *config, unsigned short i
         break;
 
       case INC_IDEAL_GAS_POLY:
-        fluidModel = new CIncIdealGasPolynomial<N_POLY_COEFFS>(Gas_ConstantND, Pressure_ThermodynamicND);
+        fluidModel = new CIncIdealGasPolynomial<N_POLY_COEFFS>(Gas_ConstantND, Pressure_ThermodynamicND, STD_REF_TEMP / config->GetTemperature_Ref());
         if (viscous) {
           /*--- Variable Cp model via polynomial. ---*/
           config->SetCp_PolyCoeffND(config->GetCp_PolyCoeff(0)/Gas_Constant_Ref, 0);
           for (iVar = 1; iVar < config->GetnPolyCoeffs(); iVar++)
             config->SetCp_PolyCoeffND(config->GetCp_PolyCoeff(iVar)*pow(Temperature_Ref,iVar)/Gas_Constant_Ref, iVar);
-          fluidModel->SetCpModel(config);
+          fluidModel->SetCpModel(config, Temperature_FreeStreamND);
         }
         fluidModel->SetTDState_T(Temperature_FreeStreamND);
         break;
diff --git a/SU2_CFD/src/solvers/CSolver.cpp b/SU2_CFD/src/solvers/CSolver.cpp
index dad6234080e1..8737d1d3b9e7 100644
--- a/SU2_CFD/src/solvers/CSolver.cpp
+++ b/SU2_CFD/src/solvers/CSolver.cpp
@@ -1834,8 +1834,6 @@ void CSolver::AdaptCFLNumber(CGeometry **geometry,
       }
     }
 
-    cout << reduceCFL << resetCFL << "\n";
-
     } /* End safe global access, now all threads update the CFL number. */
     END_SU2_OMP_SAFE_GLOBAL_ACCESS
 
diff --git a/TestCases/disc_adj_incomp_navierstokes/cylinder/heated_cylinder.cfg b/TestCases/disc_adj_incomp_navierstokes/cylinder/heated_cylinder.cfg
index 039b53f63659..7274a4b1fccb 100644
--- a/TestCases/disc_adj_incomp_navierstokes/cylinder/heated_cylinder.cfg
+++ b/TestCases/disc_adj_incomp_navierstokes/cylinder/heated_cylinder.cfg
@@ -62,7 +62,7 @@ MARKER_MONITORING= ( cylinder )
 % ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------%
 %
 NUM_METHOD_GRAD= GREEN_GAUSS
-CFL_NUMBER= 1000.0
+CFL_NUMBER= 200.0
 CFL_ADAPT= NO
 CFL_ADAPT_PARAM= ( 1.5, 0.5, 10.0, 10000.0 )
 RK_ALPHA_COEFF= ( 0.66667, 0.66667, 1.000000 )
diff --git a/TestCases/flamelet/01_laminar_premixed_ch4_flame_cfd/lam_prem_ch4_cfd.cfg b/TestCases/flamelet/01_laminar_premixed_ch4_flame_cfd/lam_prem_ch4_cfd.cfg
index 467dfd2b8da9..af94d2606353 100644
--- a/TestCases/flamelet/01_laminar_premixed_ch4_flame_cfd/lam_prem_ch4_cfd.cfg
+++ b/TestCases/flamelet/01_laminar_premixed_ch4_flame_cfd/lam_prem_ch4_cfd.cfg
@@ -13,7 +13,7 @@
 SOLVER = INC_NAVIER_STOKES
 KIND_TURB_MODEL= NONE
 MATH_PROBLEM= DIRECT
-RESTART_SOL = YES
+RESTART_SOL = NO
 %
 % ---------------- INCOMPRESSIBLE FLOW CONDITION DEFINITION -------------------%
 %
@@ -37,7 +37,8 @@ KIND_SCALAR_MODEL= FLAMELET
 DIFFUSIVITY_MODEL= FLAMELET
 VISCOSITY_MODEL= FLAMELET
 CONDUCTIVITY_MODEL= FLAMELET
-FLAME_INIT_METHOD= FLAME_FRONT
+%FLAME_INIT_METHOD= FLAME_FRONT
+FLAME_INIT_METHOD= NONE
 FLAME_INIT= (0.0032, 0.00, 0.00, 1.0, 0.1, 0.0, 1.0e-3, 0.1)
 % # progvar, enthalpy
 SPECIES_INIT = (0.0, -210000, 0.0, 0.0)
@@ -86,8 +87,10 @@ MARKER_ANALYZE_AVERAGE = AREA
 % ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------%
 %
 NUM_METHOD_GRAD= WEIGHTED_LEAST_SQUARES
-CFL_NUMBER= 50
-CFL_ADAPT= NO
+CFL_NUMBER= 100
+CFL_ADAPT= YES
+CFL_ADAPT_PARAM= ( 0.95, 1.01, 10.0, 1000, 0.01, 0)
+
 ITER= 10000
 OUTPUT_WRT_FREQ= 100
 %
@@ -115,7 +118,7 @@ CONV_RESIDUAL_MINVAL= -15
 CONV_STARTITER= 10
 CONV_CAUCHY_ELEMS= 100
 CONV_CAUCHY_EPS= 1E-6
-SCREEN_OUTPUT = INNER_ITER RMS_VELOCITY-X RMS_VELOCITY-Y RMS_PRESSURE RMS_ProgressVariable RMS_EnthalpyTot RMS_CO RMS_NOx
+SCREEN_OUTPUT = INNER_ITER RMS_VELOCITY-X RMS_VELOCITY-Y RMS_PRESSURE RMS_ProgressVariable RMS_EnthalpyTot RMS_CO RMS_NOx, AVG_CFL
 HISTORY_OUTPUT = RMS_RES AERO_COEFF FLOW_COEFF FLOW_COEFF_SURF
 VOLUME_OUTPUT = SOLUTION PRIMITIVE SOURCE RESIDUAL SENSITIVITY LOOKUP TIMESTEP
 CONV_FIELD = RMS_PRESSURE
@@ -127,8 +130,8 @@ MESH_FILENAME = mesh_structured.cgns
 MESH_OUT_FILENAME= mesh_out
 SOLUTION_FILENAME= solution
 RESTART_FILENAME= restart
-OUTPUT_FILES = (RESTART,PARAVIEW,PARAVIEW_MULTIBLOCK) 
-%OUTPUT_FILES = (RESTART) 
+%OUTPUT_FILES = (RESTART,PARAVIEW,PARAVIEW_MULTIBLOCK) 
+OUTPUT_FILES = (RESTART) 
 TABULAR_FORMAT = CSV
 CONV_FILENAME= history
 VOLUME_FILENAME= ch4_flame_cfd
diff --git a/TestCases/flamelet/05_laminar_premixed_ch4_flame_cfd_axi/lam_prem_ch4_cfd_axi.cfg b/TestCases/flamelet/05_laminar_premixed_ch4_flame_cfd_axi/lam_prem_ch4_cfd_axi.cfg
index fabcdc4981cf..51986fe7b7b1 100644
--- a/TestCases/flamelet/05_laminar_premixed_ch4_flame_cfd_axi/lam_prem_ch4_cfd_axi.cfg
+++ b/TestCases/flamelet/05_laminar_premixed_ch4_flame_cfd_axi/lam_prem_ch4_cfd_axi.cfg
@@ -13,13 +13,13 @@
 %
 SOLVER= INC_NAVIER_STOKES
 KIND_TURB_MODEL= NONE
-MATH_PROBLEM= DIRECT
+%MATH_PROBLEM= DIRECT
 RESTART_SOL= YES
 %
 % ---------------- INCOMPRESSIBLE FLOW CONDITION DEFINITION -------------------%
 %
 INC_DENSITY_MODEL= FLAMELET
-INC_ENERGY_EQUATION= YES
+INC_ENERGY_EQUATION= NO
 INC_DENSITY_INIT= 1.00
 INC_VELOCITY_INIT= (0.5, 0.0, 0.0 )
 INC_TEMPERATURE_INIT= 300.0
@@ -40,6 +40,7 @@ KIND_SCALAR_MODEL= FLAMELET
 DIFFUSIVITY_MODEL= FLAMELET
 VISCOSITY_MODEL= FLAMELET
 CONDUCTIVITY_MODEL= FLAMELET
+FLAME_INIT_METHOD= NONE
 FLAME_INIT= (0.0032, 0.0, 0.0, 1, 0.1, 0, 1e-3, 0.1)
 % # progvar, enthalpy
 SPECIES_INIT= (0.0, -210000, 0.0, 0.0)
@@ -86,8 +87,10 @@ MARKER_ANALYZE_AVERAGE= AREA
 % ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------%
 %
 NUM_METHOD_GRAD= WEIGHTED_LEAST_SQUARES
-CFL_NUMBER= 20
-CFL_ADAPT= NO
+CFL_NUMBER= 100
+CFL_ADAPT= YES
+CFL_ADAPT_PARAM= ( 0.95, 1.01, 10.0, 1000, 0.001)
+
 ITER= 10000
 OUTPUT_WRT_FREQ= 100
 %
@@ -95,8 +98,8 @@ OUTPUT_WRT_FREQ= 100
 %
 LINEAR_SOLVER= FGMRES
 LINEAR_SOLVER_PREC= ILU
-LINEAR_SOLVER_ERROR= 1E-10
-LINEAR_SOLVER_ITER= 25
+LINEAR_SOLVER_ERROR= 1E-03
+LINEAR_SOLVER_ITER= 10
 %
 % -------------------------- MULTIGRID PARAMETERS -----------------------------%
 %
@@ -115,7 +118,7 @@ CONV_RESIDUAL_MINVAL= -15
 CONV_STARTITER= 10
 CONV_CAUCHY_ELEMS= 100
 CONV_CAUCHY_EPS= 1E-6
-SCREEN_OUTPUT= INNER_ITER WALL_TIME RMS_VELOCITY-X RMS_VELOCITY-Y RMS_PRESSURE RMS_ProgressVariable RMS_EnthalpyTot
+SCREEN_OUTPUT= INNER_ITER WALL_TIME RMS_VELOCITY-X RMS_VELOCITY-Y RMS_PRESSURE RMS_ProgressVariable RMS_EnthalpyTot, AVG_CFL
 HISTORY_OUTPUT= RMS_RES AERO_COEFF FLOW_COEFF FLOW_COEFF_SURF
 VOLUME_OUTPUT= SOLUTION PRIMITIVE SOURCE RESIDUAL SENSITIVITY LOOKUP TIMESTEP
 CONV_FIELD= RMS_PRESSURE
@@ -127,8 +130,8 @@ MESH_FILENAME= mesh_axi.su2
 MESH_OUT_FILENAME= mesh_out
 SOLUTION_FILENAME= solution
 RESTART_FILENAME= restart
-%OUTPUT_FILES= (RESTART,PARAVIEW,PARAVIEW_MULTIBLOCK)
-OUTPUT_FILES= (RESTART)
+OUTPUT_FILES= (RESTART,PARAVIEW,PARAVIEW_MULTIBLOCK)
+%OUTPUT_FILES= (RESTART)
 TABULAR_FORMAT= CSV
 CONV_FILENAME= history
 VOLUME_FILENAME= flow
diff --git a/TestCases/hybrid_regression.py b/TestCases/hybrid_regression.py
index d92ee4c2465b..b796466eb09e 100644
--- a/TestCases/hybrid_regression.py
+++ b/TestCases/hybrid_regression.py
@@ -375,7 +375,7 @@ def main():
     inc_buoyancy.cfg_dir   = "incomp_navierstokes/buoyancy_cavity"
     inc_buoyancy.cfg_file  = "lam_buoyancy_cavity.cfg"
     inc_buoyancy.test_iter = 20
-    inc_buoyancy.test_vals = [-3.860456, -3.122396, 4.074516, -23.415000]
+    inc_buoyancy.test_vals = [-3.860443, -3.122399, 4.074529, -23.413000]
     test_list.append(inc_buoyancy)
 
     # Laminar heated cylinder with polynomial fluid model

From e1c6dc37525dab02ab9287945749f30cf3b9fa4f Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Tue, 30 Dec 2025 14:44:03 +0100
Subject: [PATCH 18/37] fix polynomial cp

---
 SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp b/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
index efba9fd3d4ed..e7c217e96e07 100644
--- a/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
+++ b/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
@@ -59,14 +59,9 @@ class CIncIdealGasPolynomial final : public CFluidModel {
    * \param[in] config - configuration container for the problem.
    */
   void SetCpModel(const CConfig* config, su2double val_Temperature_Ref) override {
-    const su2double t_ref = val_Temperature_Ref;
-    Enthalpy_Ref = 0.0;
-    su2double t_i = 1.0;
     for (int i = 0; i < N; ++i) {
       /*--- Note that we use cp = dh/dt here. ---*/
-      t_i *= t_ref - Std_Ref_Temp_ND;
       coeffs_[i] = config->GetCp_PolyCoeffND(i);
-      Enthalpy_Ref += coeffs_[i] * t_i / (i + 1);
     }
     Temperature_Min = config->GetTemperatureLimits(0);
   }
@@ -114,12 +109,14 @@ class CIncIdealGasPolynomial final : public CFluidModel {
     while ((abs(delta_temp_iter) > toll) && (counter++ < counter_limit)) {
       /* Evaluate the new Cp and enthalpy from the coefficients and temperature. */
       Cp_iter = coeffs_[0];
-      su2double Enthalpy_iter = coeffs_[0] * temp_iter - Enthalpy_Ref;
+      su2double tref_i = temp_iter - Std_Ref_Temp_ND;
+      su2double Enthalpy_iter = coeffs_[0] * tref_i;
       su2double t_i = 1.0;
       for (int i = 1; i < N; ++i) {
         t_i *= temp_iter;
+        tref_i *= (temp_iter - Std_Ref_Temp_ND);
         Cp_iter += coeffs_[i] * t_i;
-        Enthalpy_iter += coeffs_[i] * t_i * temp_iter / (i + 1);
+        Enthalpy_iter += coeffs_[i] * tref_i / (i + 1);
       }
 
       delta_enthalpy_iter = Enthalpy - Enthalpy_iter;
@@ -133,6 +130,7 @@ class CIncIdealGasPolynomial final : public CFluidModel {
         break;
       }
     }
+
     Temperature = temp_iter;
     Cp = Cp_iter;
     if (counter == counter_limit) {
@@ -147,6 +145,5 @@ class CIncIdealGasPolynomial final : public CFluidModel {
   su2double Gamma{0.0};        /*!< \brief Ratio of specific heats. */
   su2double Std_Ref_Temp_ND{0.0}; /*!< \brief Nondimensional standard reference temperature for enthalpy. */
   array<su2double, N> coeffs_; /*!< \brief Polynomial coefficients for heat capacity as a function of temperature. */
-  su2double Enthalpy_Ref;      /*!< \brief Enthalpy computed at the reference temperature. */
   su2double Temperature_Min;   /*!< \brief Minimum temperature value allowed in Newton-Raphson iterations. */
 };

From dc0e72f07e061e21d16ea40b37519c25525d1b96 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Tue, 30 Dec 2025 15:42:20 +0100
Subject: [PATCH 19/37] update warning

---
 SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp b/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
index e7c217e96e07..0f584ec4f404 100644
--- a/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
+++ b/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
@@ -105,7 +105,7 @@ class CIncIdealGasPolynomial final : public CFluidModel {
 
     int counter = 0;
 
-    /*--- Computing temperature given enthalpy using Newton-Raphson. ---*/
+    /*--- Compute temperature given enthalpy using Newton-Raphson. ---*/
     while ((abs(delta_temp_iter) > toll) && (counter++ < counter_limit)) {
       /* Evaluate the new Cp and enthalpy from the coefficients and temperature. */
       Cp_iter = coeffs_[0];
@@ -125,7 +125,7 @@ class CIncIdealGasPolynomial final : public CFluidModel {
 
       temp_iter += delta_temp_iter;
       if (temp_iter < Temperature_Min) {
-        cout << "Warning: Negative temperature has been found during Newton-Raphson" << endl;
+        cout << "Warning: Negative temperature has been found during Newton-Raphson." << endl;
         temp_iter = Temperature_Min;
         break;
       }
@@ -134,7 +134,7 @@ class CIncIdealGasPolynomial final : public CFluidModel {
     Temperature = temp_iter;
     Cp = Cp_iter;
     if (counter == counter_limit) {
-      cout << "Warning Newton-Raphson exceed number of max iteration in temperature computation" << endl;
+      cout << "Warning: Newton-Raphson exceeds max. iterations in temperature computation." << endl;
     }
     Density = Pressure / (Temperature * Gas_Constant);
     Cv = Cp / Gamma;

From cf8baeca45f3b4e48b4e60598cddc635e60edaa8 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Tue, 30 Dec 2025 20:31:21 +0100
Subject: [PATCH 20/37] update easy regression tests

---
 TestCases/hybrid_regression.py      |  8 ++++----
 TestCases/hybrid_regression_AD.py   |  4 ++--
 TestCases/parallel_regression.py    |  8 ++++----
 TestCases/parallel_regression_AD.py |  2 +-
 TestCases/serial_regression.py      | 10 +++++-----
 5 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/TestCases/hybrid_regression.py b/TestCases/hybrid_regression.py
index b796466eb09e..708ba4d6109f 100644
--- a/TestCases/hybrid_regression.py
+++ b/TestCases/hybrid_regression.py
@@ -383,8 +383,8 @@ def main():
     inc_poly_cylinder.cfg_dir   = "incomp_navierstokes/cylinder"
     inc_poly_cylinder.cfg_file  = "poly_cylinder.cfg"
     inc_poly_cylinder.test_iter = 20
-    inc_poly_cylinder.test_vals         = [-8.241953, -2.424330, 0.027284, 1.909617, -173.010000]
-    inc_poly_cylinder.test_vals_aarch64 = [-8.241953, -2.424330, 0.027284, 1.909617, -173.010000]
+    inc_poly_cylinder.test_vals         = [-8.260165, -2.445453, 0.027209, 1.915447, -171.620000]
+    inc_poly_cylinder.test_vals_aarch64 = [-8.260165, -2.445453, 0.027209, 1.915447, -171.620000]
     test_list.append(inc_poly_cylinder)
 
     # X-coarse laminar bend as a mixed element CGNS test
@@ -665,8 +665,8 @@ def main():
     slinc_steady.cfg_dir   = "sliding_interface/incompressible_steady"
     slinc_steady.cfg_file  = "config.cfg"
     slinc_steady.test_iter = 19
-    slinc_steady.test_vals         = [19.000000, -1.154873, -1.378119]
-    slinc_steady.test_vals_aarch64 = [19.000000, -1.048446, -1.324274]
+    slinc_steady.test_vals         = [19.000000, -1.048972, -1.324971]
+    slinc_steady.test_vals_aarch64 = [19.000000, -1.048972, -1.324971]
     slinc_steady.multizone = True
     test_list.append(slinc_steady)
 
diff --git a/TestCases/hybrid_regression_AD.py b/TestCases/hybrid_regression_AD.py
index e1ba90d6a1d0..89bd80ee8f37 100644
--- a/TestCases/hybrid_regression_AD.py
+++ b/TestCases/hybrid_regression_AD.py
@@ -111,8 +111,8 @@ def main():
     discadj_incomp_cylinder.cfg_dir   = "disc_adj_incomp_navierstokes/cylinder"
     discadj_incomp_cylinder.cfg_file  = "heated_cylinder.cfg"
     discadj_incomp_cylinder.test_iter = 20
-    discadj_incomp_cylinder.test_vals         = [20.000000, -5.098033, -3.842740, 0.000000]
-    discadj_incomp_cylinder.test_vals_aarch64 = [20.000000, -5.098033, -3.842740, 0.000000]
+    discadj_incomp_cylinder.test_vals         = [20.000000, -1.671920, -6.254841, 0.000000]
+    discadj_incomp_cylinder.test_vals_aarch64 = [20.000000, -1.671920, -6.254841, 0.000000]
     discadj_incomp_cylinder.tol_aarch64 = 2e-1
     test_list.append(discadj_incomp_cylinder)
 
diff --git a/TestCases/parallel_regression.py b/TestCases/parallel_regression.py
index b9ff817a716f..865385c0172b 100755
--- a/TestCases/parallel_regression.py
+++ b/TestCases/parallel_regression.py
@@ -611,7 +611,7 @@ def main():
     inc_poly_cylinder.cfg_dir   = "incomp_navierstokes/cylinder"
     inc_poly_cylinder.cfg_file  = "poly_cylinder.cfg"
     inc_poly_cylinder.test_iter = 20
-    inc_poly_cylinder.test_vals = [-8.030976, -2.362995, 0.006829, 1.923532, -172.590000]
+    inc_poly_cylinder.test_vals = [-8.030822, -2.383534, 0.006612, 1.929173, -171.210000]
     test_list.append(inc_poly_cylinder)
 
     # X-coarse laminar bend as a mixed element CGNS test
@@ -635,7 +635,7 @@ def main():
     inc_heatTransfer_BC.cfg_dir   = "incomp_navierstokes/streamwise_periodic/chtPinArray_2d"
     inc_heatTransfer_BC.cfg_file  = "BC_HeatTransfer.cfg"
     inc_heatTransfer_BC.test_iter = 50
-    inc_heatTransfer_BC.test_vals = [-8.686723, -7.601245, -8.072766, 1.864213, -1669.800000]
+    inc_heatTransfer_BC.test_vals = [-8.904266, -7.745636, -8.064003, -1.079197, -1671.000000]
     test_list.append(inc_heatTransfer_BC)
 
     ############################
@@ -1209,7 +1209,7 @@ def main():
     slinc_steady.cfg_dir   = "sliding_interface/incompressible_steady"
     slinc_steady.cfg_file  = "config.cfg"
     slinc_steady.test_iter = 19
-    slinc_steady.test_vals = [19.000000, -1.131557, -1.370471]
+    slinc_steady.test_vals = [19.000000, -1.013427, -1.222965]
     slinc_steady.timeout   = 100
     slinc_steady.tol       = 0.00002
     slinc_steady.multizone = True
@@ -1319,7 +1319,7 @@ def main():
     p1rad.cfg_dir   = "radiation/p1model"
     p1rad.cfg_file  = "configp1.cfg"
     p1rad.test_iter = 50
-    p1rad.test_vals = [-7.743666, -7.921411, -2.111848, 0.098302, -47.897000]
+    p1rad.test_vals = [-7.700974, -7.734765, -2.061661, 0.382811, -57.861000]
     test_list.append(p1rad)
 
 
diff --git a/TestCases/parallel_regression_AD.py b/TestCases/parallel_regression_AD.py
index f800dbdc7697..9d05feaaf4f5 100644
--- a/TestCases/parallel_regression_AD.py
+++ b/TestCases/parallel_regression_AD.py
@@ -116,7 +116,7 @@ def main():
     discadj_incomp_cylinder.cfg_dir   = "disc_adj_incomp_navierstokes/cylinder"
     discadj_incomp_cylinder.cfg_file  = "heated_cylinder.cfg"
     discadj_incomp_cylinder.test_iter = 20
-    discadj_incomp_cylinder.test_vals = [20.000000, -5.181765, -3.840710, 0.000000]
+    discadj_incomp_cylinder.test_vals = [20.000000, -1.652493, -6.202452, 0.000000]
     test_list.append(discadj_incomp_cylinder)
 
     ######################################
diff --git a/TestCases/serial_regression.py b/TestCases/serial_regression.py
index 3d7d89691dcd..115a02aef135 100755
--- a/TestCases/serial_regression.py
+++ b/TestCases/serial_regression.py
@@ -415,7 +415,7 @@ def main():
     inc_poly_cylinder.cfg_dir   = "incomp_navierstokes/cylinder"
     inc_poly_cylinder.cfg_file  = "poly_cylinder.cfg"
     inc_poly_cylinder.test_iter = 20
-    inc_poly_cylinder.test_vals = [-8.232551, -2.412865, 0.010163, 1.895333, -172.760000]
+    inc_poly_cylinder.test_vals = [-8.241365, -2.434357, 0.010085, 1.901399, -171.350000]
     test_list.append(inc_poly_cylinder)
 
     # X-coarse laminar bend as a mixed element CGNS test
@@ -458,7 +458,7 @@ def main():
     inc_turb_wallfunction_flatplate_sst.cfg_dir   = "wallfunctions/flatplate/incompressible_SST"
     inc_turb_wallfunction_flatplate_sst.cfg_file  = "turb_SST_flatplate.cfg"
     inc_turb_wallfunction_flatplate_sst.test_iter = 10
-    inc_turb_wallfunction_flatplate_sst.test_vals = [-6.881887, -5.731983, -6.725181, -2.618754, -7.189701, -2.050891, 10.000000, -2.027265, 0.001155, 0.003172, 0.000000]
+    inc_turb_wallfunction_flatplate_sst.test_vals = [-6.879863, -5.731934, -6.732450, -4.240641, -7.189679, -2.050873, 10.000000, -4.007590, 0.001161, 0.003172, 0.000000]
     test_list.append(inc_turb_wallfunction_flatplate_sst)
 
     # FLAT PLATE, WALL FUNCTIONS, INCOMPRESSIBLE SA
@@ -466,7 +466,7 @@ def main():
     inc_turb_wallfunction_flatplate_sa.cfg_dir   = "wallfunctions/flatplate/incompressible_SA"
     inc_turb_wallfunction_flatplate_sa.cfg_file  = "turb_SA_flatplate.cfg"
     inc_turb_wallfunction_flatplate_sa.test_iter = 10
-    inc_turb_wallfunction_flatplate_sa.test_vals = [-6.894473, -5.715971, -6.744286, -2.631311, -9.550134, 10.000000, -2.017104, 0.001027, 0.003759]
+    inc_turb_wallfunction_flatplate_sa.test_vals = [-6.892397, -5.715934, -6.750379, -4.240551, -9.550026, 10.000000, -4.008745, 0.001030, 0.003759]
     test_list.append(inc_turb_wallfunction_flatplate_sa)
 
     ####################
@@ -986,7 +986,7 @@ def main():
     slinc_steady.cfg_dir   = "sliding_interface/incompressible_steady"
     slinc_steady.cfg_file  = "config.cfg"
     slinc_steady.test_iter = 19
-    slinc_steady.test_vals = [19.000000, -1.148249, -1.398402]
+    slinc_steady.test_vals = [19.000000, -1.050011, -1.303591]
     slinc_steady.timeout   = 100
     slinc_steady.multizone = True
     test_list.append(slinc_steady)
@@ -1098,7 +1098,7 @@ def main():
     p1rad.cfg_dir   = "radiation/p1model"
     p1rad.cfg_file  = "configp1.cfg"
     p1rad.test_iter = 50
-    p1rad.test_vals = [-8.284673, -8.008659, -2.424204, 0.389030, -56.560000]
+    p1rad.test_vals = [-7.939639, -7.898740, -2.238329, 0.388591, -56.886000]
     test_list.append(p1rad)
 
     # ###############################

From b52a9ab2ec901dc39437ec29d7911bdb241aa8be Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Thu, 1 Jan 2026 13:11:43 +0100
Subject: [PATCH 21/37] update parallel regressions

---
 .../lam_prem_ch4_cfd.cfg                          |  2 +-
 .../lam_partial_prem_ch4_cfd.cfg                  | 15 +++++++++------
 TestCases/parallel_regression.py                  | 12 ++++++------
 3 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/TestCases/flamelet/01_laminar_premixed_ch4_flame_cfd/lam_prem_ch4_cfd.cfg b/TestCases/flamelet/01_laminar_premixed_ch4_flame_cfd/lam_prem_ch4_cfd.cfg
index af94d2606353..ab1ce53175a2 100644
--- a/TestCases/flamelet/01_laminar_premixed_ch4_flame_cfd/lam_prem_ch4_cfd.cfg
+++ b/TestCases/flamelet/01_laminar_premixed_ch4_flame_cfd/lam_prem_ch4_cfd.cfg
@@ -13,7 +13,7 @@
 SOLVER = INC_NAVIER_STOKES
 KIND_TURB_MODEL= NONE
 MATH_PROBLEM= DIRECT
-RESTART_SOL = NO
+RESTART_SOL = YES
 %
 % ---------------- INCOMPRESSIBLE FLOW CONDITION DEFINITION -------------------%
 %
diff --git a/TestCases/flamelet/06_laminar_partial_premixed_ch4_flame_cfd/lam_partial_prem_ch4_cfd.cfg b/TestCases/flamelet/06_laminar_partial_premixed_ch4_flame_cfd/lam_partial_prem_ch4_cfd.cfg
index 810747ca0a50..06194170d4ff 100644
--- a/TestCases/flamelet/06_laminar_partial_premixed_ch4_flame_cfd/lam_partial_prem_ch4_cfd.cfg
+++ b/TestCases/flamelet/06_laminar_partial_premixed_ch4_flame_cfd/lam_partial_prem_ch4_cfd.cfg
@@ -18,7 +18,7 @@ RESTART_SOL= YES
 % ---------------- INCOMPRESSIBLE FLOW CONDITION DEFINITION -------------------%
 %
 INC_DENSITY_MODEL= VARIABLE
-INC_ENERGY_EQUATION = YES
+INC_ENERGY_EQUATION = NO
 INC_DENSITY_INIT= 1.00
 INC_VELOCITY_INIT= (0.7, 0.0, 0.0 )
 INC_TEMPERATURE_INIT= 300.0
@@ -39,6 +39,8 @@ KIND_SCALAR_MODEL= FLAMELET
 DIFFUSIVITY_MODEL= FLAMELET
 VISCOSITY_MODEL= FLAMELET
 CONDUCTIVITY_MODEL= FLAMELET
+FLAME_INIT_METHOD= NONE 
+%FLAME_INIT_METHOD= FLAME_FRONT
 FLAME_INIT= (0.003, 0.00, 0.00, 1.0, 0.0, 0.0, 1e-4, 1.0)
 % # progvar, enthalpy, mixture fraction, Y-CO, Y-CO2
 SPECIES_INIT = (0.0,	-253498.718914723, 0.05, 0.0, 0.0)
@@ -86,17 +88,18 @@ MARKER_OUTLET= (outlet, 0.0)
 % ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------%
 %
 NUM_METHOD_GRAD= WEIGHTED_LEAST_SQUARES
-CFL_NUMBER= 20
+CFL_NUMBER= 10
 CFL_ADAPT= NO
-ITER= 10
+CFL_ADAPT_PARAM= ( 0.9, 1.01, 1.0, 1000, 0.001)
+ITER= 10000
 OUTPUT_WRT_FREQ= 20
 %
 % ------------------------ LINEAR SOLVER DEFINITION ---------------------------%
 %
 LINEAR_SOLVER= FGMRES
 LINEAR_SOLVER_PREC= ILU
-LINEAR_SOLVER_ERROR= 1E-03
-LINEAR_SOLVER_ITER= 10
+LINEAR_SOLVER_ERROR= 1E-10
+LINEAR_SOLVER_ITER= 25
 %
 % -------------------------- MULTIGRID PARAMETERS -----------------------------%
 %
@@ -115,7 +118,7 @@ CONV_RESIDUAL_MINVAL= -15
 CONV_STARTITER= 10
 CONV_CAUCHY_ELEMS= 100
 CONV_CAUCHY_EPS= 1E-6
-SCREEN_OUTPUT = INNER_ITER RMS_VELOCITY-X RMS_VELOCITY-Y RMS_PRESSURE RMS_ProgressVariable RMS_EnthalpyTot RMS_MixtureFraction RMS_CO2
+SCREEN_OUTPUT = INNER_ITER RMS_VELOCITY-X RMS_VELOCITY-Y RMS_PRESSURE RMS_ProgressVariable RMS_EnthalpyTot RMS_MixtureFraction RMS_CO2, AVG_CFL
 HISTORY_OUTPUT = RMS_RES AERO_COEFF FLOW_COEFF FLOW_COEFF_SURF
 VOLUME_OUTPUT = SOLUTION PRIMITIVE SOURCE RESIDUAL SENSITIVITY LOOKUP TIMESTEP
 CONV_FIELD = RMS_PRESSURE
diff --git a/TestCases/parallel_regression.py b/TestCases/parallel_regression.py
index 865385c0172b..3c1513d8e14f 100755
--- a/TestCases/parallel_regression.py
+++ b/TestCases/parallel_regression.py
@@ -1594,7 +1594,7 @@ def main():
     species2_primitiveVenturi_mixingmodel_viscosity.cfg_dir   = "species_transport/venturi_primitive_3species"
     species2_primitiveVenturi_mixingmodel_viscosity.cfg_file  = "species2_primitiveVenturi_mixingmodel_viscosity.cfg"
     species2_primitiveVenturi_mixingmodel_viscosity.test_iter = 50
-    species2_primitiveVenturi_mixingmodel_viscosity.test_vals = [-5.239118, -3.624947, -3.874462, -7.535191, -5.130418, 5.000000, -1.677376, 5.000000, -3.493540, 5.000000, -2.085009, 2.495398, 0.985401, 0.600225, 0.909772]
+    species2_primitiveVenturi_mixingmodel_viscosity.test_vals = [-5.239996, -3.625478, -3.874990, -7.535233, -5.130497, 5.000000, -1.677719, 5.000000, -3.494206, 5.000000, -2.085734, 2.494985, 0.985388, 0.599841, 0.909757]
     test_list.append(species2_primitiveVenturi_mixingmodel_viscosity)
 
     # 2 species (1 eq) primitive venturi mixing using mixing model including heat capacity and mass diffusivity
@@ -1634,7 +1634,7 @@ def main():
     species2_primitiveVenturi.cfg_dir   = "species_transport/venturi_primitive_3species"
     species2_primitiveVenturi.cfg_file  = "species2_primitiveVenturi.cfg"
     species2_primitiveVenturi.test_iter = 50
-    species2_primitiveVenturi.test_vals = [-5.558877, -4.529177, -4.568986, -5.394648, -0.920813, -5.679485, 5.000000, -0.597225, 5.000000, -2.602079, 5.000000, -0.548939, 0.000037, 0.000037, 0.000000, 0.000000]
+    species2_primitiveVenturi.test_vals = [-5.557355, -4.528649, -4.567282, -5.392656, -0.920718, -5.677129, 5.000000, -0.597625, 5.000000, -2.601553, 5.000000, -0.550169, 0.000035, 0.000035, 0.000000, 0.000000]
     test_list.append(species2_primitiveVenturi)
 
     # 2 species (1 eq) primitive venturi mixing with bounded scalar transport
@@ -1642,7 +1642,7 @@ def main():
     species_primitiveVenturi_boundedscalar.cfg_dir     = "species_transport/venturi_primitive_3species"
     species_primitiveVenturi_boundedscalar.cfg_file    = "species2_primitiveVenturi_boundedscalar.cfg"
     species_primitiveVenturi_boundedscalar.test_iter   = 50
-    species_primitiveVenturi_boundedscalar.test_vals   = [-5.539052, -4.376789, -4.477172, -5.579444, -0.871002, -5.633907, 5.000000, -1.460361, 5.000000, -4.141551, 5.000000, -1.727113, 0.000438, 0.000438, 0.000000, 0.000000]
+    species_primitiveVenturi_boundedscalar.test_vals   = [-5.539052, -4.376789, -4.477172, -5.579444, -0.871003, -5.633907, 5.000000, -1.460377, 5.000000, -4.141552, 5.000000, -1.727113, 0.000438, 0.000438, 0.000000, 0.000000]
     test_list.append(species_primitiveVenturi_boundedscalar)
 
     # 2 species (1 eq) primitive venturi mixing using mixing model including inlet markers for turbulent intensity and viscosity ratios
@@ -1650,7 +1650,7 @@ def main():
     species2_primitiveVenturi_mixingmodel_TURBULENT_MARKERS.cfg_dir   = "species_transport/venturi_primitive_3species"
     species2_primitiveVenturi_mixingmodel_TURBULENT_MARKERS.cfg_file  = "species2_primitiveVenturi_mixingmodel_TURBULENT_MARKERS.cfg"
     species2_primitiveVenturi_mixingmodel_TURBULENT_MARKERS.test_iter = 50
-    species2_primitiveVenturi_mixingmodel_TURBULENT_MARKERS.test_vals = [-4.767010, -1.818299, -1.842427, -0.615338, 1.366173, -3.921308, 21.000000, -5.213096, 9.000000, -5.422897, 4.000000, -5.919063, 2.000000, 1.000000, 0.000000, 1.000000]
+    species2_primitiveVenturi_mixingmodel_TURBULENT_MARKERS.test_vals = [-4.782077, -1.837073, -1.862970, -0.641171, 1.349304, -3.929006, 21.000000, -5.212393, 9.000000, -5.455072, 4.000000, -5.915343, 2.000000, 1.000000, 0.000000, 1.000000]
     test_list.append(species2_primitiveVenturi_mixingmodel_TURBULENT_MARKERS)
 
     # 3 species (2 eq) primitive venturi mixing with inlet files.
@@ -1659,7 +1659,7 @@ def main():
     species3_primitiveVenturi_inletFile.cfg_dir   = "species_transport/venturi_primitive_3species"
     species3_primitiveVenturi_inletFile.cfg_file  = "species3_primitiveVenturi_inletFile.cfg"
     species3_primitiveVenturi_inletFile.test_iter = 50
-    species3_primitiveVenturi_inletFile.test_vals = [-5.537438, -4.503863, -4.553632, -5.400874, -0.945967, -5.818774, -5.945211, 5.000000, -0.544749, 5.000000, -2.599435, 5.000000, -0.596360]
+    species3_primitiveVenturi_inletFile.test_vals = [-5.541163, -4.505905, -4.557116, -5.398846, -0.938219, -5.817818, -5.944195, 5.000000, -0.555895, 5.000000, -2.598254, 5.000000, -0.597122]
     test_list.append(species3_primitiveVenturi_inletFile)
 
     # 3 species (2 eq) primitive venturi mixing with new flux and value boundary conditions 
@@ -1667,7 +1667,7 @@ def main():
     species3_primitiveVenturi_fluxvalue.cfg_dir   = "species_transport/venturi_primitive_3species"
     species3_primitiveVenturi_fluxvalue.cfg_file  = "species3_primitiveVenturi_flux_value.cfg"
     species3_primitiveVenturi_fluxvalue.test_iter = 50
-    species3_primitiveVenturi_fluxvalue.test_vals = [-4.563229, -5.504499, -0.861681, -5.822963, -6.458352, 1.257908, 0.122218, 0.317705, 0.817985, 0.241494, 0.102507, 0.004981, 0.134006]
+    species3_primitiveVenturi_fluxvalue.test_vals = [-4.563242, -5.504658, -0.861266, -5.822957, -6.458367, 1.257912, 0.122219, 0.317705, 0.817988, 0.241494, 0.102507, 0.004981, 0.134006]
     test_list.append(species3_primitiveVenturi_fluxvalue)
 
     # rectangle passive transport validation

From f61a783a4bab33512023a9b8d8d08111fb4eaa55 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Thu, 1 Jan 2026 16:29:37 +0100
Subject: [PATCH 22/37] update regressions

---
 .../cylinder/heated_cylinder.cfg                      |  5 +++--
 TestCases/py_wrapper/turbulent_premixed_psi/psi.cfg   | 11 ++++-------
 TestCases/py_wrapper/turbulent_premixed_psi/run.py    |  2 +-
 TestCases/serial_regression_AD.py                     |  2 +-
 4 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/TestCases/disc_adj_incomp_navierstokes/cylinder/heated_cylinder.cfg b/TestCases/disc_adj_incomp_navierstokes/cylinder/heated_cylinder.cfg
index 7274a4b1fccb..650a9667d7c6 100644
--- a/TestCases/disc_adj_incomp_navierstokes/cylinder/heated_cylinder.cfg
+++ b/TestCases/disc_adj_incomp_navierstokes/cylinder/heated_cylinder.cfg
@@ -12,7 +12,7 @@
 %
 SOLVER= INC_NAVIER_STOKES
 KIND_TURB_MODEL= NONE
-MATH_PROBLEM= DISCRETE_ADJOINT
+%MATH_PROBLEM= DISCRETE_ADJOINT
 RESTART_SOL= NO
 
 % ---------------- INCOMPRESSIBLE FLOW CONDITION DEFINITION -------------------%
@@ -62,6 +62,7 @@ MARKER_MONITORING= ( cylinder )
 % ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------%
 %
 NUM_METHOD_GRAD= GREEN_GAUSS
+%CFL_NUMBER= 1000.0
 CFL_NUMBER= 200.0
 CFL_ADAPT= NO
 CFL_ADAPT_PARAM= ( 1.5, 0.5, 10.0, 10000.0 )
@@ -120,7 +121,7 @@ GRAD_OBJFUNC_FILENAME= of_grad
 SURFACE_FILENAME= surface_flow
 SURFACE_ADJ_FILENAME= surface_adjoint
 OUTPUT_WRT_FREQ= 250
-SCREEN_OUTPUT= (INNER_ITER, RMS_ADJ_PRESSURE, RMS_ADJ_ENTHALPY, SENS_PRESS, SENS_AOA)
+SCREEN_OUTPUT= (INNER_ITER, RMS_PRESSURE, RMS_ENTHALPY, RMS_ADJ_PRESSURE, RMS_ADJ_ENTHALPY, SENS_PRESS, SENS_AOA)
 
 % ----------------------- DESIGN VARIABLE PARAMETERS --------------------------%
 %
diff --git a/TestCases/py_wrapper/turbulent_premixed_psi/psi.cfg b/TestCases/py_wrapper/turbulent_premixed_psi/psi.cfg
index c01c2de84cb1..1efa7ff0c68b 100644
--- a/TestCases/py_wrapper/turbulent_premixed_psi/psi.cfg
+++ b/TestCases/py_wrapper/turbulent_premixed_psi/psi.cfg
@@ -17,9 +17,6 @@ SST_OPTIONS= V1994m
 
 RESTART_SOL= YES
 
-MGLEVEL= 0
-%
-
 % temperature and density 
 FREESTREAM_TEMPERATURE = 673
 FREESTREAM_DENSITY = 2.55
@@ -86,11 +83,11 @@ MARKER_OUTLET= ( outlet, 0.0 )
 %
 NUM_METHOD_GRAD= WEIGHTED_LEAST_SQUARES
 %
-CFL_NUMBER= 2.00
+CFL_NUMBER= 50.0
 CFL_REDUCTION_SPECIES= 1.0
 CFL_REDUCTION_TURB= 1.0
 %CFL_ADAPT= YES
-CFL_ADAPT= YES
+CFL_ADAPT= NO
 CFL_ADAPT_PARAM= ( 0.95, 1.01, 1.0, 250, 1.0e-4, 0)
 
 %
@@ -143,7 +140,7 @@ MUSCL_TURB= NO
 % --------------------------- CONVERGENCE PARAMETERS --------------------------%
 %
 CONV_FIELD= RMS_PRESSURE, RMS_VELOCITY-X, RMS_VELOCITY-Y, RMS_TKE, RMS_SPECIES
-CONV_RESIDUAL_MINVAL= -18
+CONV_RESIDUAL_MINVAL= -12
 CONV_STARTITER= 10
 %
 % ------------------------- INPUT/OUTPUT INFORMATION --------------------------%
@@ -160,7 +157,7 @@ CONV_FILENAME= history
 MARKER_ANALYZE= gas_inlet, air_axial_inlet, outlet
 MARKER_ANALYZE_AVERAGE= AREA
 %
-OUTPUT_FILES= RESTART, RESTART_ASCII, PARAVIEW_MULTIBLOCK
+OUTPUT_FILES= RESTART, PARAVIEW_MULTIBLOCK
 VOLUME_OUTPUT= RESIDUAL, PRIMITIVE, SPECIES_UDS_0
 OUTPUT_WRT_FREQ= 100
 %
diff --git a/TestCases/py_wrapper/turbulent_premixed_psi/run.py b/TestCases/py_wrapper/turbulent_premixed_psi/run.py
index 1f355f135e6f..f54017b9ce65 100644
--- a/TestCases/py_wrapper/turbulent_premixed_psi/run.py
+++ b/TestCases/py_wrapper/turbulent_premixed_psi/run.py
@@ -223,7 +223,7 @@ def main():
   sys.stdout.flush()
 
   # run N iterations
-  for inner_iter in range(10):
+  for inner_iter in range(1000):
     if (rank==0):
       print("python iteration ", inner_iter)
 
diff --git a/TestCases/serial_regression_AD.py b/TestCases/serial_regression_AD.py
index 35e3131e5c58..ed0b21faf850 100644
--- a/TestCases/serial_regression_AD.py
+++ b/TestCases/serial_regression_AD.py
@@ -219,7 +219,7 @@ def main():
     discadj_cht.cfg_dir   = "coupled_cht/disc_adj_incomp_2d"
     discadj_cht.cfg_file  = "cht_2d_3cylinders.cfg"
     discadj_cht.test_iter = 10
-    discadj_cht.test_vals = [-6.308199, -3.086023, -3.086024, -3.086024]
+    discadj_cht.test_vals = [-6.111521, -2.668836, -2.669558, -2.669595]
     test_list.append(discadj_cht)
 
     ######################################

From f1c071e2a56b118dc10db99fac67500405f29f4f Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Thu, 1 Jan 2026 19:55:31 +0100
Subject: [PATCH 23/37] fix bug in nondimensionalization

---
 SU2_CFD/include/fluid/CFluidScalar.hpp           |  1 +
 SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp | 16 ++++++++--------
 SU2_CFD/src/fluid/CFluidScalar.cpp               |  9 +++++----
 SU2_CFD/src/solvers/CIncEulerSolver.cpp          |  4 ++++
 TestCases/parallel_regression.py                 |  8 ++++----
 .../py_wrapper/turbulent_premixed_psi/run.py     |  2 +-
 6 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/SU2_CFD/include/fluid/CFluidScalar.hpp b/SU2_CFD/include/fluid/CFluidScalar.hpp
index ba97fa5451e4..1e6d8e9c2ad1 100644
--- a/SU2_CFD/include/fluid/CFluidScalar.hpp
+++ b/SU2_CFD/include/fluid/CFluidScalar.hpp
@@ -43,6 +43,7 @@ class CFluidScalar final : public CFluidModel {
   su2double Gas_Constant;                 /*!< \brief Specific gas constant. */
   const su2double Pressure_Thermodynamic; /*!< \brief Constant pressure thermodynamic. */
   const su2double GasConstant_Ref;        /*!< \brief Gas constant reference needed for Nondimensional problems. */
+  const su2double Std_Ref_Temp_ND;        /*!< \brief Nondimensional standard reference temperature for enthalpy. */
   const su2double Prandtl_Turb_Number;    /*!< \brief Prandlt turbulent number.*/
   const su2double Schmidt_Turb_Number;    /*!< \brief Schmidt turbulent number.*/
 
diff --git a/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp b/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
index 0f584ec4f404..01b141752193 100644
--- a/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
+++ b/SU2_CFD/include/fluid/CIncIdealGasPolynomial.hpp
@@ -77,14 +77,14 @@ class CIncIdealGasPolynomial final : public CFluidModel {
 
     /* Evaluate the new Cp and enthalpy from the coefficients and temperature. */
     Cp = coeffs_[0];
-    su2double tref_i = t - Std_Ref_Temp_ND;
-    Enthalpy = coeffs_[0] * tref_i;
+    Enthalpy = coeffs_[0] * (t - Std_Ref_Temp_ND);
     su2double t_i = 1.0;
+    su2double tref_i = 1.0;
     for (int i = 1; i < N; ++i) {
       t_i *= t;
-      tref_i *= (t - Std_Ref_Temp_ND);
+      tref_i *= Std_Ref_Temp_ND;
       Cp += coeffs_[i] * t_i;
-      Enthalpy += coeffs_[i] * tref_i / (i + 1);
+      Enthalpy += coeffs_[i] * (t_i * t - tref_i * Std_Ref_Temp_ND) / (i + 1);
     }
     Cv = Cp / Gamma;
   }
@@ -109,14 +109,14 @@ class CIncIdealGasPolynomial final : public CFluidModel {
     while ((abs(delta_temp_iter) > toll) && (counter++ < counter_limit)) {
       /* Evaluate the new Cp and enthalpy from the coefficients and temperature. */
       Cp_iter = coeffs_[0];
-      su2double tref_i = temp_iter - Std_Ref_Temp_ND;
-      su2double Enthalpy_iter = coeffs_[0] * tref_i;
+      su2double Enthalpy_iter = coeffs_[0] * (temp_iter - Std_Ref_Temp_ND);
       su2double t_i = 1.0;
+      su2double tref_i = 1.0;
       for (int i = 1; i < N; ++i) {
         t_i *= temp_iter;
-        tref_i *= (temp_iter - Std_Ref_Temp_ND);
+        tref_i *= Std_Ref_Temp_ND;
         Cp_iter += coeffs_[i] * t_i;
-        Enthalpy_iter += coeffs_[i] * tref_i / (i + 1);
+        Enthalpy_iter += coeffs_[i] * (t_i * temp_iter - tref_i * Std_Ref_Temp_ND) / (i + 1);
       }
 
       delta_enthalpy_iter = Enthalpy - Enthalpy_iter;
diff --git a/SU2_CFD/src/fluid/CFluidScalar.cpp b/SU2_CFD/src/fluid/CFluidScalar.cpp
index 4b384c521f9c..f71f221fa07c 100644
--- a/SU2_CFD/src/fluid/CFluidScalar.cpp
+++ b/SU2_CFD/src/fluid/CFluidScalar.cpp
@@ -46,6 +46,7 @@ CFluidScalar::CFluidScalar(su2double value_pressure_operating, const CConfig* co
       n_species_mixture(config->GetnSpecies() + 1),
       Pressure_Thermodynamic(value_pressure_operating),
       GasConstant_Ref(config->GetGas_Constant_Ref()),
+      Std_Ref_Temp_ND(STD_REF_TEMP / config->GetTemperature_Ref()),
       Prandtl_Turb_Number(config->GetPrandtl_Turb()),
       Schmidt_Turb_Number(config->GetSchmidt_Number_Turbulent()),
       wilke(config->GetKind_MixingViscosityModel() == MIXINGVISCOSITYMODEL::WILKE),
@@ -218,14 +219,14 @@ su2double CFluidScalar::ComputeEnthalpyFromT(const su2double val_temperature, co
    * depend on temperature, but it does depend on mixture composition, enthalpy is directly computed from
    * the expression h_s = Cp(T - T_ref).
    */
-  su2double val_Enthalpy = Cp * (val_temperature - STD_REF_TEMP);
+  su2double val_Enthalpy = Cp * (val_temperature - Std_Ref_Temp_ND);
   return val_Enthalpy;
 }
 
 void CFluidScalar::GetEnthalpyDiffusivity(su2double* enthalpy_diffusions) const {
-  const su2double enthalpy_species_N = specificHeat[n_species_mixture - 1] * (Temperature - STD_REF_TEMP);
+  const su2double enthalpy_species_N = specificHeat[n_species_mixture - 1] * (Temperature - Std_Ref_Temp_ND);
   for (int iVar = 0; iVar < n_species_mixture - 1; iVar++) {
-    const su2double enthalpy_species_i = specificHeat[iVar] * (Temperature - STD_REF_TEMP);
+    const su2double enthalpy_species_i = specificHeat[iVar] * (Temperature - Std_Ref_Temp_ND);
     enthalpy_diffusions[iVar] = Density * (enthalpy_species_i * massDiffusivity[iVar] -
                                            enthalpy_species_N * massDiffusivity[n_species_mixture - 1]);
     enthalpy_diffusions[iVar] += Mu_Turb * (enthalpy_species_i - enthalpy_species_N) / Schmidt_Turb_Number;
@@ -270,7 +271,7 @@ void CFluidScalar::SetTDState_h(const su2double val_enthalpy, const su2double* v
    * depend on temperature, but it does depend on mixture composition, temperature is directly solved from the
    * expression h_s = Cp(T - T_ref).
    */
-  Temperature = val_enthalpy / Cp + STD_REF_TEMP;
+  Temperature = val_enthalpy / Cp + Std_Ref_Temp_ND;
   Density = Pressure_Thermodynamic / (Temperature * Gas_Constant);
   Cv = Cp - Gas_Constant;
 
diff --git a/SU2_CFD/src/solvers/CIncEulerSolver.cpp b/SU2_CFD/src/solvers/CIncEulerSolver.cpp
index e11c2d012fc6..a3e3cfefad1f 100644
--- a/SU2_CFD/src/solvers/CIncEulerSolver.cpp
+++ b/SU2_CFD/src/solvers/CIncEulerSolver.cpp
@@ -384,9 +384,13 @@ void CIncEulerSolver::SetNondimensionalization(CConfig *config, unsigned short i
   }
   else if (config->GetRef_Inc_NonDim() == INITIAL_VALUES) {
     Density_Ref     = Density_FreeStream;
+    cout << "Density_Ref: " << Density_Ref << endl;
     Velocity_Ref    = ModVel_FreeStream;
+    cout << "Velocity_Ref: " << Velocity_Ref << endl;
     Temperature_Ref = Temperature_FreeStream;
+    cout << "Temperature_Ref: " << Temperature_Ref << endl;
     Pressure_Ref    = Density_Ref*Velocity_Ref*Velocity_Ref;
+    cout << "Pressure_Ref: " << Pressure_Ref << endl;
   }
   else if (config->GetRef_Inc_NonDim() == REFERENCE_VALUES) {
     Density_Ref     = config->GetInc_Density_Ref();
diff --git a/TestCases/parallel_regression.py b/TestCases/parallel_regression.py
index 02f5791dd8d7..18e1b6e35fc4 100755
--- a/TestCases/parallel_regression.py
+++ b/TestCases/parallel_regression.py
@@ -47,7 +47,7 @@ def main():
     cfd_flamelet_ch4.cfg_dir = "flamelet/01_laminar_premixed_ch4_flame_cfd"
     cfd_flamelet_ch4.cfg_file = "lam_prem_ch4_cfd.cfg"
     cfd_flamelet_ch4.test_iter = 10
-    cfd_flamelet_ch4.test_vals = [-11.167959, -10.484323, -12.764338, -5.876637, -13.407242, -17.032153]
+    cfd_flamelet_ch4.test_vals = [-14.971554, -15.910509, -9.042920, -16.513197, -19.488582, 104.940000]
     cfd_flamelet_ch4.new_output = True
     test_list.append(cfd_flamelet_ch4)
 
@@ -56,7 +56,7 @@ def main():
     cfd_flamelet_ch4_axi.cfg_dir = "flamelet/05_laminar_premixed_ch4_flame_cfd_axi"
     cfd_flamelet_ch4_axi.cfg_file = "lam_prem_ch4_cfd_axi.cfg"
     cfd_flamelet_ch4_axi.test_iter = 10
-    cfd_flamelet_ch4_axi.test_vals = [-10.083640, -11.327840, -10.714798, -12.750041, -6.112100]
+    cfd_flamelet_ch4_axi.test_vals = [-11.259602, -10.020810, -11.852797, -4.909130, 95.000000]
     cfd_flamelet_ch4_axi.new_output = True
     test_list.append(cfd_flamelet_ch4_axi)
 
@@ -65,7 +65,7 @@ def main():
     cfd_flamelet_ch4_partial_premix.cfg_dir = "flamelet/06_laminar_partial_premixed_ch4_flame_cfd"
     cfd_flamelet_ch4_partial_premix.cfg_file = "lam_partial_prem_ch4_cfd.cfg"
     cfd_flamelet_ch4_partial_premix.test_iter = 10
-    cfd_flamelet_ch4_partial_premix.test_vals = [-8.734770, -11.306471, -3.675618, -12.808760, -11.088026]
+    cfd_flamelet_ch4_partial_premix.test_vals = [-10.482722, -3.621023, -12.938151, -10.154391, 10.000000]
     cfd_flamelet_ch4_partial_premix.new_output = True
     test_list.append(cfd_flamelet_ch4_partial_premix)
 
@@ -1504,7 +1504,7 @@ def main():
     pywrapper_buoyancy.cfg_dir = "py_wrapper/custom_source_buoyancy"
     pywrapper_buoyancy.cfg_file = "lam_buoyancy_cavity.cfg"
     pywrapper_buoyancy.test_iter = 0
-    pywrapper_buoyancy.test_vals = [-11.864224, -12.149668, -3.539309, -6.119375]
+    pywrapper_buoyancy.test_vals = [-13.314107, -13.764877, -13.136439, -5.379183]
     pywrapper_buoyancy.test_vals_aarch64 = [-17.746018, -17.460693, -17.430708, -12.260624]
     pywrapper_buoyancy.command = TestCase.Command("mpirun -np 2", "python", "run.py")
     test_list.append(pywrapper_buoyancy)
diff --git a/TestCases/py_wrapper/turbulent_premixed_psi/run.py b/TestCases/py_wrapper/turbulent_premixed_psi/run.py
index f54017b9ce65..1f355f135e6f 100644
--- a/TestCases/py_wrapper/turbulent_premixed_psi/run.py
+++ b/TestCases/py_wrapper/turbulent_premixed_psi/run.py
@@ -223,7 +223,7 @@ def main():
   sys.stdout.flush()
 
   # run N iterations
-  for inner_iter in range(1000):
+  for inner_iter in range(10):
     if (rank==0):
       print("python iteration ", inner_iter)
 

From 4bc2f5806ee092037dc68439e4906c90c6992652 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Fri, 2 Jan 2026 00:11:30 +0100
Subject: [PATCH 24/37] update regressions

---
 TestCases/hybrid_regression.py    | 2 +-
 TestCases/parallel_regression.py  | 4 ++--
 TestCases/serial_regression.py    | 2 +-
 TestCases/serial_regression_AD.py | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/TestCases/hybrid_regression.py b/TestCases/hybrid_regression.py
index 0c5816d9d599..633c802b93be 100644
--- a/TestCases/hybrid_regression.py
+++ b/TestCases/hybrid_regression.py
@@ -383,7 +383,7 @@ def main():
     inc_poly_cylinder.cfg_dir   = "incomp_navierstokes/cylinder"
     inc_poly_cylinder.cfg_file  = "poly_cylinder.cfg"
     inc_poly_cylinder.test_iter = 20
-    inc_poly_cylinder.test_vals         = [-8.260165, -2.445453, 0.027209, 1.915447, -171.620000]
+    inc_poly_cylinder.test_vals         = [-8.241953, -2.424330, 0.027284, 1.909617, -173.010000]
     inc_poly_cylinder.test_vals_aarch64 = [-8.260165, -2.445453, 0.027209, 1.915447, -171.620000]
     test_list.append(inc_poly_cylinder)
 
diff --git a/TestCases/parallel_regression.py b/TestCases/parallel_regression.py
index 18e1b6e35fc4..686dbae3a90e 100755
--- a/TestCases/parallel_regression.py
+++ b/TestCases/parallel_regression.py
@@ -611,7 +611,7 @@ def main():
     inc_poly_cylinder.cfg_dir   = "incomp_navierstokes/cylinder"
     inc_poly_cylinder.cfg_file  = "poly_cylinder.cfg"
     inc_poly_cylinder.test_iter = 20
-    inc_poly_cylinder.test_vals = [-8.030822, -2.383534, 0.006612, 1.929173, -171.210000]
+    inc_poly_cylinder.test_vals = [-8.030976, -2.362995, 0.006829, 1.923532, -172.590000]
     test_list.append(inc_poly_cylinder)
 
     # X-coarse laminar bend as a mixed element CGNS test
@@ -1514,7 +1514,7 @@ def main():
     pywrapper_zimont.cfg_dir = "py_wrapper/turbulent_premixed_psi"
     pywrapper_zimont.cfg_file = "psi.cfg"
     pywrapper_zimont.test_iter = 0
-    pywrapper_zimont.test_vals = [-5.532006, -4.663972, -5.838306, -4.316956, -2.073665, -4.453762]
+    pywrapper_zimont.test_vals = [-9.317943, -0.377235, -1.091632, -0.502950, 2.968250, -1.242417]
     pywrapper_zimont.command = TestCase.Command("mpirun -np 2", "python", "run.py")
     test_list.append(pywrapper_zimont)
 
diff --git a/TestCases/serial_regression.py b/TestCases/serial_regression.py
index 13abe8dbbce1..ac56cc6ae05d 100755
--- a/TestCases/serial_regression.py
+++ b/TestCases/serial_regression.py
@@ -415,7 +415,7 @@ def main():
     inc_poly_cylinder.cfg_dir   = "incomp_navierstokes/cylinder"
     inc_poly_cylinder.cfg_file  = "poly_cylinder.cfg"
     inc_poly_cylinder.test_iter = 20
-    inc_poly_cylinder.test_vals = [-8.241365, -2.434357, 0.010085, 1.901399, -171.350000]
+    inc_poly_cylinder.test_vals = [-8.232551, -2.412865, 0.010163, 1.895333, -172.760000]
     test_list.append(inc_poly_cylinder)
 
     # X-coarse laminar bend as a mixed element CGNS test
diff --git a/TestCases/serial_regression_AD.py b/TestCases/serial_regression_AD.py
index ed0b21faf850..613125c69d7b 100644
--- a/TestCases/serial_regression_AD.py
+++ b/TestCases/serial_regression_AD.py
@@ -120,7 +120,7 @@ def main():
     discadj_incomp_cylinder.cfg_dir   = "disc_adj_incomp_navierstokes/cylinder"
     discadj_incomp_cylinder.cfg_file  = "heated_cylinder.cfg"
     discadj_incomp_cylinder.test_iter = 20
-    discadj_incomp_cylinder.test_vals = [20.000000, -5.097821, -3.842739, 0.000000]
+    discadj_incomp_cylinder.test_vals = [20.000000, -1.672307, -6.247612, 0.000000]
     test_list.append(discadj_incomp_cylinder)
 
     #######################################################

From b7e413c4edbedd8b74a79d9dd6cb8e807fb4773e Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Fri, 2 Jan 2026 22:59:24 +0100
Subject: [PATCH 25/37] update regressions

---
 .../lam_prem_ch4_cht_cfd_fluid.cfg                    |  3 ++-
 .../lam_prem_ch4_cht_cfd_master.cfg                   |  2 +-
 .../laminar_premixed_h2_flame_cfd.cfg                 | 11 ++++++-----
 .../chtPinArray_2d/of_grad_findiff.csv.ref            |  4 ++--
 4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/TestCases/flamelet/03_laminar_premixed_ch4_flame_cht_cfd/lam_prem_ch4_cht_cfd_fluid.cfg b/TestCases/flamelet/03_laminar_premixed_ch4_flame_cht_cfd/lam_prem_ch4_cht_cfd_fluid.cfg
index af8e562b0cdb..005bea4123af 100644
--- a/TestCases/flamelet/03_laminar_premixed_ch4_flame_cht_cfd/lam_prem_ch4_cht_cfd_fluid.cfg
+++ b/TestCases/flamelet/03_laminar_premixed_ch4_flame_cht_cfd/lam_prem_ch4_cht_cfd_fluid.cfg
@@ -57,7 +57,8 @@ FLUID_MODEL= FLUID_FLAMELET
 FILENAMES_INTERPOLATOR= (fgm_ch4.drg)
 CONTROLLING_VARIABLE_NAMES= (ProgressVariable, EnthalpyTot)
 CONTROLLING_VARIABLE_SOURCE_NAMES= (ProdRateTot_PV, NULL)
-FLAME_INIT_METHOD= NONE
+FLAME_INIT_METHOD= NONE 
+%FLAME_INIT_METHOD= FLAME_FRONT
 FLAME_INIT= (0.004, 0.0, 0.0, 1.0, 0.0, 0.0, 0.2e-3, 1.0)
 
 % -------------------- SPECIES TRANSPORT ---------------------------------------%
diff --git a/TestCases/flamelet/03_laminar_premixed_ch4_flame_cht_cfd/lam_prem_ch4_cht_cfd_master.cfg b/TestCases/flamelet/03_laminar_premixed_ch4_flame_cht_cfd/lam_prem_ch4_cht_cfd_master.cfg
index cb9dafa62bae..4704aedef68b 100644
--- a/TestCases/flamelet/03_laminar_premixed_ch4_flame_cht_cfd/lam_prem_ch4_cht_cfd_master.cfg
+++ b/TestCases/flamelet/03_laminar_premixed_ch4_flame_cht_cfd/lam_prem_ch4_cht_cfd_master.cfg
@@ -35,7 +35,7 @@ RESTART_FILENAME= restart
 RESTART_ADJ_FILENAME= restart_adj
 
 TIME_DOMAIN= NO
-OUTER_ITER= 10
+OUTER_ITER= 100
 
 OUTPUT_WRT_FREQ= 100
 SCREEN_WRT_FREQ_INNER= 1
diff --git a/TestCases/flamelet/07_laminar_premixed_h2_flame_cfd/laminar_premixed_h2_flame_cfd.cfg b/TestCases/flamelet/07_laminar_premixed_h2_flame_cfd/laminar_premixed_h2_flame_cfd.cfg
index 3f294865a179..93328224dc0b 100644
--- a/TestCases/flamelet/07_laminar_premixed_h2_flame_cfd/laminar_premixed_h2_flame_cfd.cfg
+++ b/TestCases/flamelet/07_laminar_premixed_h2_flame_cfd/laminar_premixed_h2_flame_cfd.cfg
@@ -12,8 +12,8 @@
 %
 SOLVER = INC_NAVIER_STOKES
 KIND_TURB_MODEL= NONE
-MATH_PROBLEM= DIRECT
-RESTART_SOL =YES
+%MATH_PROBLEM= DIRECT
+RESTART_SOL= YES
 % ---------------- INCOMPRESSIBLE FLOW CONDITION DEFINITION -------------------%
 %
 INC_DENSITY_MODEL= VARIABLE
@@ -37,7 +37,8 @@ PREFERENTIAL_DIFFUSION= YES
 % -------------------- SCALAR TRANSPORT ---------------------------------------%
 %
 % Using an artificial spark to ignite the solution at some location and iteration
-FLAME_INIT_METHOD= SPARK
+FLAME_INIT_METHOD= NONE
+%FLAME_INIT_METHOD= SPARK 
 % Spark parameters in order:
 % x-location of spark center (m)
 % y-location of spark center (m)
@@ -77,9 +78,9 @@ MARKER_ANALYZE_AVERAGE = AREA
 % ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------%
 %
 NUM_METHOD_GRAD= GREEN_GAUSS
-CFL_NUMBER =50
+CFL_NUMBER= 50
 CFL_ADAPT= NO
-ITER=5
+ITER=500
 OUTPUT_WRT_FREQ= 20
 % ------------------------ LINEAR SOLVER DEFINITION ---------------------------%
 %
diff --git a/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff.csv.ref b/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff.csv.ref
index 2d925e77a8cd..af480e5fa85c 100644
--- a/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff.csv.ref
+++ b/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff.csv.ref
@@ -1,2 +1,2 @@
-"VARIABLE"      , "AVG_DENSITY[0]", "AVG_ENTHALPY[0]", "AVG_NORMALVEL[0]", "DRAG[0]"       , "EFFICIENCY[0]" , "FORCE_X[0]"    , "FORCE_Y[0]"    , "FORCE_Z[0]"    , "LIFT[0]"       , "MOMENT_X[0]"   , "MOMENT_Y[0]"   , "MOMENT_Z[0]"   , "SIDEFORCE[0]"  , "SURFACE_MACH[0]", "SURFACE_MASSFLOW[0]", "SURFACE_MOM_DISTORTION[0]", "SURFACE_PRESSURE_DROP[0]", "SURFACE_SECONDARY[0]", "SURFACE_SECOND_OVER_UNIFORM[0]", "SURFACE_STATIC_PRESSURE[0]", "SURFACE_STATIC_TEMPERATURE[0]", "SURFACE_TOTAL_PRESSURE[0]", "SURFACE_TOTAL_TEMPERATURE[0]", "SURFACE_UNIFORMITY[0]", "AVG_TEMPERATURE[1]", "TOTAL_HEATFLUX[1]", "FINDIFF_STEP"
-0               , 0.0             , 0.0             , 3.3307000000906214e-08, 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0                , 0.0                      , 0.0                     , 0.0                 , 0.0                           , 0.0                       , 0.0                          , -9.999996564147295       , -10.000007932831068         , 0.0                  , -80.0000009348878 , -360.00000136482413, 1e-08
+"VARIABLE"      , "AVG_DENSITY[0]", "AVG_ENTHALPY[0]", "AVG_NORMALVEL[0]", "DRAG[0]"       , "EFFICIENCY[0]" , "FORCE_X[0]"    , "FORCE_Y[0]"    , "FORCE_Z[0]"    , "LIFT[0]"       , "MOMENT_X[0]"   , "MOMENT_Y[0]"   , "MOMENT_Z[0]"   , "SIDEFORCE[0]"  , "SURFACE_MACH[0]", "SURFACE_MASSFLOW[0]", "SURFACE_MOM_DISTORTION[0]", "SURFACE_PRESSURE_DROP[0]", "SURFACE_SECONDARY[0]", "SURFACE_SECOND_OVER_UNIFORM[0]", "SURFACE_STATIC_PRESSURE[0]", "SURFACE_STATIC_TEMPERATURE[0]", "SURFACE_TOTAL_PRESSURE[0]", "SURFACE_TOTAL_TEMPERATURE[0]", "SURFACE_UNIFORMITY[0]", "AVG_TEMPERATURE[1]", "TOTAL_HEATFLUX[1]", "FINDIFF_STEP"  
+0               , 0.0             , -409999.99619089067, -4.4410000000756306e-08, 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.12000000160217184, 3.3300000005652e-08, -0.2800000009628434      , 0.0                     , 1.1799999977135656  , 1.5699999966756195            , 2599.999999119973         , -119.99999287581886          , 3870.0000004610047       , -109.99999631167157         , 0.7999999995789153   , -210.00000174353772, 14480.000004368776, 1e-08           

From 9331f6535dbbb963c930d58abc8e27fffef58e4e Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Fri, 2 Jan 2026 23:28:38 +0100
Subject: [PATCH 26/37] fixing tutorials

---
 .github/workflows/regression.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/regression.yml b/.github/workflows/regression.yml
index 6bddf426aab7..c3d21e54c897 100644
--- a/.github/workflows/regression.yml
+++ b/.github/workflows/regression.yml
@@ -211,7 +211,7 @@ jobs:
         uses: docker://ghcr.io/su2code/su2/test-su2:250717-1402
         with:
           # -t <Tutorials-branch> -c <Testcases-branch>
-          args: -b ${{github.ref}} -t develop -c fix_enthalpy -s ${{matrix.testscript}}
+          args: -b ${{github.ref}} -t fix_enthalpy -c fix_enthalpy -s ${{matrix.testscript}}
       - name: Cleanup
         uses: docker://ghcr.io/su2code/su2/test-su2:250717-1402
         with:

From c6e8e770ad564010ae6154b98bc5a6d141930b2a Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Sun, 4 Jan 2026 22:31:41 +0100
Subject: [PATCH 27/37] fixing tutorials and add relaxation factor

---
 SU2_CFD/src/solvers/CSpeciesFlameletSolver.cpp   | 11 ++++++-----
 .../lam_prem_ch4_cfd.cfg                         |  8 ++++----
 .../lam_prem_ch4_cht_ad_fluid.cfg                | 16 +++++++++-------
 .../lam_prem_ch4_cht_ad_master.cfg               |  4 ++--
 .../lam_prem_ch4_cht_ad_solid.cfg                |  7 ++++---
 TestCases/parallel_regression.py                 |  2 +-
 TestCases/parallel_regression_AD.py              |  8 ++++----
 TestCases/tutorials.py                           | 16 ++++++++--------
 8 files changed, 38 insertions(+), 34 deletions(-)

diff --git a/SU2_CFD/src/solvers/CSpeciesFlameletSolver.cpp b/SU2_CFD/src/solvers/CSpeciesFlameletSolver.cpp
index a1163faa7513..efe1b4a4c7d6 100644
--- a/SU2_CFD/src/solvers/CSpeciesFlameletSolver.cpp
+++ b/SU2_CFD/src/solvers/CSpeciesFlameletSolver.cpp
@@ -211,6 +211,7 @@ void CSpeciesFlameletSolver::SetInitialCondition(CGeometry** geometry, CSolver**
 
     for (unsigned long i_mesh = 0; i_mesh <= config->GetnMGLevels(); i_mesh++) {
       fluid_model_local = solver_container[i_mesh][FLOW_SOL]->GetFluidModel();
+      prog_burnt = GetBurntProgressVariable(fluid_model_local, scalar_init);
 
       for (auto iVar = 0u; iVar < nVar; iVar++) scalar_init[iVar] = config->GetSpecies_Init()[iVar];
 
@@ -225,8 +226,6 @@ void CSpeciesFlameletSolver::SetInitialCondition(CGeometry** geometry, CSolver**
 
         if (flame_front_ignition) {
 
-          prog_burnt = GetBurntProgressVariable(fluid_model_local, scalar_init);
-
           /*--- Determine if point is above or below the plane, assuming the normal
             is pointing towards the burned region. ---*/
           point_loc = 0.0;
@@ -301,6 +300,7 @@ void CSpeciesFlameletSolver::SetInitialCondition(CGeometry** geometry, CSolver**
         cout << " Number of points in unburnt region: " << n_points_unburnt_global << "." << endl;
         cout << " Number of points in burnt region  : " << n_points_burnt_global << "." << endl;
         cout << " Number of points in flame zone    : " << n_points_flame_global << "." << endl;
+        cout << " Burnt progress Variable           : " << prog_burnt << "." << endl;
       }
 
       if (n_not_in_domain_global > 0)
@@ -406,7 +406,6 @@ void CSpeciesFlameletSolver::BC_Inlet(CGeometry* geometry, CSolver** solver_cont
   su2double enth_inlet;
   GetEnthFromTemp(solver_container[FLOW_SOL]->GetFluidModel(), temp_inlet, config->GetInlet_SpeciesVal(Marker_Tag),
                   &enth_inlet);
-
   SU2_OMP_FOR_STAT(OMP_MIN_SIZE)
   for (auto iVertex = 0u; iVertex < geometry->nVertex[val_marker]; iVertex++) {
     Inlet_SpeciesVars[val_marker][iVertex][I_ENTH] = enth_inlet;
@@ -758,6 +757,8 @@ unsigned long CSpeciesFlameletSolver::GetEnthFromTemp(CFluidModel* fluid_model,
   su2double delta_temp_iter = 1e10;
   unsigned long exit_code = 0;
   const int counter_limit = 1000;
+  /*--- Relaxation factor for Newton iterations. ---*/
+  const su2double RelaxAlpha = 0.75;
 
   int counter = 0;
 
@@ -774,9 +775,10 @@ unsigned long CSpeciesFlameletSolver::GetEnthFromTemp(CFluidModel* fluid_model,
 
     delta_temp_iter = val_temp - Temperature;
 
-    delta_enth = Cp * delta_temp_iter;
+    delta_enth = RelaxAlpha * Cp * delta_temp_iter;
 
     enth_iter += delta_enth;
+
   }
 
   *val_enth = enth_iter;
@@ -791,7 +793,6 @@ unsigned long CSpeciesFlameletSolver::GetEnthFromTemp(CFluidModel* fluid_model,
 su2double CSpeciesFlameletSolver::GetBurntProgressVariable(CFluidModel* fluid_model, const su2double* scalar_solution) {
   su2double scalars[MAXNVAR], delta = 1e-3;
   for (auto iVar = 0u; iVar < nVar; iVar++) scalars[iVar] = scalar_solution[iVar];
-
   bool outside = false;
   while (!outside) {
     fluid_model->SetTDState_T(300, scalars);
diff --git a/TestCases/flamelet/01_laminar_premixed_ch4_flame_cfd/lam_prem_ch4_cfd.cfg b/TestCases/flamelet/01_laminar_premixed_ch4_flame_cfd/lam_prem_ch4_cfd.cfg
index ab1ce53175a2..c22ac2efcd3c 100644
--- a/TestCases/flamelet/01_laminar_premixed_ch4_flame_cfd/lam_prem_ch4_cfd.cfg
+++ b/TestCases/flamelet/01_laminar_premixed_ch4_flame_cfd/lam_prem_ch4_cfd.cfg
@@ -33,7 +33,7 @@ CONTROLLING_VARIABLE_SOURCE_NAMES = (ProdRateTot_PV, NULL)
 %
 % -------------------- SCALAR TRANSPORT ---------------------------------------%
 %
-KIND_SCALAR_MODEL= FLAMELET      
+KIND_SCALAR_MODEL= FLAMELET
 DIFFUSIVITY_MODEL= FLAMELET
 VISCOSITY_MODEL= FLAMELET
 CONDUCTIVITY_MODEL= FLAMELET
@@ -130,12 +130,12 @@ MESH_FILENAME = mesh_structured.cgns
 MESH_OUT_FILENAME= mesh_out
 SOLUTION_FILENAME= solution
 RESTART_FILENAME= restart
-%OUTPUT_FILES = (RESTART,PARAVIEW,PARAVIEW_MULTIBLOCK) 
-OUTPUT_FILES = (RESTART) 
+%OUTPUT_FILES = (RESTART,PARAVIEW,PARAVIEW_MULTIBLOCK)
+OUTPUT_FILES = (RESTART)
 TABULAR_FORMAT = CSV
 CONV_FILENAME= history
 VOLUME_FILENAME= ch4_flame_cfd
 SURFACE_FILENAME= surface_flow
-WRT_PERFORMANCE = NO 
+WRT_PERFORMANCE = NO
 SCREEN_WRT_FREQ_INNER = 1
 SCREEN_WRT_FREQ_OUTER = 1
diff --git a/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg b/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg
index b251e54182a8..c7eada303242 100644
--- a/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg
+++ b/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg
@@ -15,13 +15,13 @@ WRT_ZONE_HIST= YES
 
 %SCREEN_OUTPUT= INNER_ITER WALL_TIME RMS_PRESSURE RMS_VELOCITY-X RMS_VELOCITY-Y RMS_TKE RMS_DISSIPATION LINSOL_ITER LINSOL_RESIDUAL RMS_ADJ_PRESSURE RMS_ADJ_VELOCITY-X RMS_ADJ_VELOCITY-Y
 
-SCREEN_OUTPUT= INNER_ITER WALL_TIME RMS_ADJ_PRESSURE RMS_ADJ_VELOCITY-X RMS_ADJ_VELOCITY-Y RMS_ADJ_ProgressVariable RMS_ADJ_EnthalpyTot RMS_ADJ_Y-CO RMS_ADJ_Y-NOx_tot
+SCREEN_OUTPUT= INNER_ITER WALL_TIME RMS_ADJ_PRESSURE RMS_ADJ_VELOCITY-X RMS_ADJ_VELOCITY-Y RMS_ADJ_ProgressVariable RMS_ADJ_EnthalpyTot RMS_ADJ_Y-CO RMS_ADJ_Y-NOx_tot LINSOL_RESIDUAL LINSOL_ITER
 
 HISTORY_OUTPUT= RMS_RES AERO_COEFF FLOW_COEFF FLOW_COEFF_SURF
 
 VOLUME_OUTPUT= SOLUTION PRIMITIVE SOURCE RESIDUAL LOOKUP
 
-OUTPUT_FILES= ( RESTART_ASCII)
+OUTPUT_FILES= ( RESTART_ASCII, PARAVIEW)
 
 WRT_RESTART_COMPACT= NO
 
@@ -38,7 +38,7 @@ INLET_MATCHING_TOLERANCE= 1e-5
 INC_INLET_TYPE= VELOCITY_INLET
 
 MARKER_INLET= (inlet, 300.0, 0.4, 1.0, 0.0, 0.0)
-MARKER_INLET_SPECIES= (inlet, 0.0, 0.0, 0.0, 0.0)
+MARKER_INLET_SPECIES= (inlet, 0.0, -100000.0, 0.0, 0.0)
 
 INC_OUTLET_TYPE= PRESSURE_OUTLET
 MARKER_OUTLET= (outlet, 0.0)
@@ -59,6 +59,8 @@ FLUID_MODEL= FLUID_FLAMELET
 FILENAMES_INTERPOLATOR= (fgm_ch4.drg)
 CONTROLLING_VARIABLE_NAMES= (ProgressVariable, EnthalpyTot)
 CONTROLLING_VARIABLE_SOURCE_NAMES= (ProdRateTot_PV, NULL)
+FLAME_INIT_METHOD= FLAME_FRONT
+%FLAME_INIT_METHOD= NONE 
 FLAME_INIT= (0.004, 0.0, 0.0, 1, 0, 0, 0.2e-3, 1)
 
 % -------------------- SPECIES TRANSPORT ---------------------------------------%
@@ -77,7 +79,7 @@ SLOPE_LIMITER_SPECIES= NONE
 
 TIME_DISCRE_SPECIES= EULER_IMPLICIT
 
-SPECIES_INIT= (0, 0, 0, 0)
+SPECIES_INIT= (0, -204000.0, 0, 0)
 SPECIES_CLIPPING= NO
 LOOKUP_NAMES= (MolarWeightMix, Conductivity, HeatRelease, Diffusivity, \
     ProdRatePos_Y-CO,  ProdRateNegScaled_Y-CO  ,\
@@ -94,15 +96,15 @@ VISCOSITY_MODEL= FLAMELET
 
 %NUM_METHOD_GRAD= GREEN_GAUSS
 NUM_METHOD_GRAD= WEIGHTED_LEAST_SQUARES
-CFL_NUMBER= 25
+CFL_NUMBER= 10
 CFL_ADAPT= NO
 
 % ------------------------ LINEAR SOLVER DEFINITION ---------------------------%
 
 LINEAR_SOLVER= BCGSTAB
 LINEAR_SOLVER_PREC= ILU
-LINEAR_SOLVER_ERROR= 1E-10
-LINEAR_SOLVER_ITER= 20
+LINEAR_SOLVER_ERROR= 1E-06
+LINEAR_SOLVER_ITER= 100
 
 % -------------------- FLOW NUMERICAL METHOD DEFINITION -----------------------%
 
diff --git a/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_master.cfg b/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_master.cfg
index 91524aea8eaf..7a9eb7debc38 100644
--- a/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_master.cfg
+++ b/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_master.cfg
@@ -44,12 +44,12 @@ OUTER_ITER = 1100
 OUTPUT_WRT_FREQ= 50
 SCREEN_WRT_FREQ_INNER= 1
 SCREEN_WRT_FREQ_OUTER= 1
-SCREEN_OUTPUT= OUTER_ITER, BGS_RES[0], BGS_RES[1]
+SCREEN_OUTPUT= OUTER_ITER, BGS_RES[0], BGS_RES[1] LINSOL_RESIDUAL[1] LINSOL_ITER[1] 
 
 WRT_VOLUME_OVERWRITE= YES
 
 %WRT_ZONE_CONV= YES
-CONV_RESIDUAL_MINVAL= -20
+CONV_RESIDUAL_MINVAL= -14
 
 VOLUME_FILENAME= fluid
 
diff --git a/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_solid.cfg b/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_solid.cfg
index 3767a165b1bb..68ec9a5e6cab 100644
--- a/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_solid.cfg
+++ b/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_solid.cfg
@@ -7,7 +7,7 @@ MARKER_PLOTTING= ( NONE )
 MARKER_MONITORING= ( NONE )
 
 WRT_ZONE_HIST= YES
-OUTPUT_FILES= ( RESTART_ASCII )
+OUTPUT_FILES= ( RESTART_ASCII, PARAVIEW )
 
 INC_NONDIM= DIMENSIONAL
 
@@ -34,14 +34,14 @@ TIME_DISCRE_HEAT= EULER_IMPLICIT
 % ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------%
 
 NUM_METHOD_GRAD= WEIGHTED_LEAST_SQUARES
-CFL_NUMBER= 250
+CFL_NUMBER= 25
 CFL_ADAPT= NO
 
 % ------------------------ LINEAR SOLVER DEFINITION ---------------------------%
 
 LINEAR_SOLVER= BCGSTAB
 LINEAR_SOLVER_PREC= ILU
-LINEAR_SOLVER_ERROR= 1e-16
+LINEAR_SOLVER_ERROR= 1e-06
 LINEAR_SOLVER_ITER= 100
 
 % ------------------------- INPUT/OUTPUT INFORMATION --------------------------%
@@ -54,4 +54,5 @@ VALUE_OBJFUNC_FILENAME= of_eval
 SURFACE_FILENAME= surface_solid
 SURFACE_ADJ_FILENAME= surface_adjoint
 
+SCREEN_OUTPUT= INNER_ITER WALL_TIME RMS_TEMPERATURE LINSOL_ITER LINSOL_RESIDUAL 
 
diff --git a/TestCases/parallel_regression.py b/TestCases/parallel_regression.py
index a15a6d96a0ef..8ac5aa8d8979 100755
--- a/TestCases/parallel_regression.py
+++ b/TestCases/parallel_regression.py
@@ -74,7 +74,7 @@ def main():
     cfd_flamelet_h2.cfg_dir = "flamelet/07_laminar_premixed_h2_flame_cfd"
     cfd_flamelet_h2.cfg_file = "laminar_premixed_h2_flame_cfd.cfg"
     cfd_flamelet_h2.test_iter = 5
-    cfd_flamelet_h2.test_vals = [-9.984960, -9.843830, -3.289852, -11.338450]
+    cfd_flamelet_h2.test_vals = [-8.036958, -8.372668, -1.842800, -9.388446]
     cfd_flamelet_h2.new_output = True
     test_list.append(cfd_flamelet_h2)
 
diff --git a/TestCases/parallel_regression_AD.py b/TestCases/parallel_regression_AD.py
index 5694c0444529..9dd012e0c995 100644
--- a/TestCases/parallel_regression_AD.py
+++ b/TestCases/parallel_regression_AD.py
@@ -256,7 +256,7 @@ def main():
     discadj_heat.cfg_dir   = "disc_adj_heat"
     discadj_heat.cfg_file  = "disc_adj_heat.cfg"
     discadj_heat.test_iter = 10
-    discadj_heat.test_vals = [-1.928244, 0.730865, 0.000000, -3.993500]
+    discadj_heat.test_vals = [-1.880390, 0.759804, 0.000000, -4.486700]
     test_list.append(discadj_heat)
 
     ###################################
@@ -290,7 +290,7 @@ def main():
     discadj_cht.cfg_dir   = "coupled_cht/disc_adj_incomp_2d"
     discadj_cht.cfg_file  = "cht_2d_3cylinders.cfg"
     discadj_cht.test_iter = 10
-    discadj_cht.test_vals = [-6.131109, -2.564634, -2.565220, -2.565303]
+    discadj_cht.test_vals = [-6.111499, -2.668835, -2.669557, -2.669594]
     test_list.append(discadj_cht)
 
     # 2D DA cht streamwise periodic case, 2 zones, avg temp objective
@@ -298,7 +298,7 @@ def main():
     da_sp_pinArray_cht_2d_dp_hf.cfg_dir   = "incomp_navierstokes/streamwise_periodic/chtPinArray_2d"
     da_sp_pinArray_cht_2d_dp_hf.cfg_file  = "DA_configMaster.cfg"
     da_sp_pinArray_cht_2d_dp_hf.test_iter = 100
-    da_sp_pinArray_cht_2d_dp_hf.test_vals = [-3.907317, -5.155811, -3.183956]
+    da_sp_pinArray_cht_2d_dp_hf.test_vals = [-4.697305, -4.335384, -4.726171]
     da_sp_pinArray_cht_2d_dp_hf.multizone = True
     test_list.append(da_sp_pinArray_cht_2d_dp_hf)
 
@@ -316,7 +316,7 @@ def main():
     da_unsteadyCHT_cylinder.cfg_dir   = "coupled_cht/disc_adj_unsteadyCHT_cylinder"
     da_unsteadyCHT_cylinder.cfg_file  = "chtMaster.cfg"
     da_unsteadyCHT_cylinder.test_iter = 2
-    da_unsteadyCHT_cylinder.test_vals         = [-8.479629, -9.239920, -9.234868, -15.934511, -13.662012, 0.000000, 89.932000, 0.295190]
+    da_unsteadyCHT_cylinder.test_vals         = [-8.479629, -9.239920, -9.234868, -15.934511, -13.662033, 0.000000, 10.627000, 0.295190]
     da_unsteadyCHT_cylinder.test_vals_aarch64 = [-8.479629, -9.239920, -9.234868, -15.934511, -13.662012, 0.000000, 89.932000, 0.295190]
     da_unsteadyCHT_cylinder.unsteady  = True
     da_unsteadyCHT_cylinder.multizone = True
diff --git a/TestCases/tutorials.py b/TestCases/tutorials.py
index dae35afba4b4..3e88ce26e7a2 100644
--- a/TestCases/tutorials.py
+++ b/TestCases/tutorials.py
@@ -49,7 +49,7 @@ def main():
     cht_incompressible_unsteady.cfg_dir   = "../Tutorials/multiphysics/unsteady_cht/"
     cht_incompressible_unsteady.cfg_file  = "cht_2d_3cylinders.cfg"
     cht_incompressible_unsteady.test_iter = 2
-    cht_incompressible_unsteady.test_vals = [-1.742894, -3.075372, -0.080399, -0.080399, -0.080399, -11.163219, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 238.240000] #last columns
+    cht_incompressible_unsteady.test_vals = [-2.661401, -0.080399, -0.080399, -0.080399, -12.421963, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 238.240000] #last columns
     cht_incompressible_unsteady.multizone = True
     cht_incompressible_unsteady.unsteady  = True
     test_list.append(cht_incompressible_unsteady)
@@ -80,8 +80,8 @@ def main():
     sp_pinArray_2d_mf_hf.cfg_dir   = "../Tutorials/incompressible_flow/Inc_Streamwise_Periodic"
     sp_pinArray_2d_mf_hf.cfg_file  = "sp_pinArray_2d_mf_hf.cfg"
     sp_pinArray_2d_mf_hf.test_iter = 25
-    sp_pinArray_2d_mf_hf.test_vals = [-4.684477, 0.844369, -0.755565, 241.872175]
-    sp_pinArray_2d_mf_hf.test_vals_aarch64 = [-4.686092, 1.387918, -0.755447, 241.878841]
+    sp_pinArray_2d_mf_hf.test_vals = [-4.683630, -0.755570, 241.872160]
+    sp_pinArray_2d_mf_hf.test_vals_aarch64 = [-4.683630, -0.755570, 241.872160]
     test_list.append(sp_pinArray_2d_mf_hf)
 
     # 2D pin case pressure drop periodic with heatflux BC and temperature periodicity
@@ -89,8 +89,8 @@ def main():
     sp_pinArray_2d_dp_hf_tp.cfg_dir   = "../Tutorials/incompressible_flow/Inc_Streamwise_Periodic"
     sp_pinArray_2d_dp_hf_tp.cfg_file  = "sp_pinArray_2d_dp_hf_tp.cfg"
     sp_pinArray_2d_dp_hf_tp.test_iter = 25
-    sp_pinArray_2d_dp_hf_tp.test_vals = [-4.739886, 0.520841, -0.713547, 208.023676]
-    sp_pinArray_2d_dp_hf_tp.test_vals_aarch64 = [-4.733643, 1.325195, -0.713411, 208.023676]
+    sp_pinArray_2d_dp_hf_tp.test_vals = [-4.739709, -0.713547, 208.023676
+    sp_pinArray_2d_dp_hf_tp.test_vals_aarch64 = [-4.739709, -0.713547, 208.023676]
     test_list.append(sp_pinArray_2d_dp_hf_tp)
 
     # 90 degree pipe bend with wall functions from the experiments of Sudo et al.
@@ -136,7 +136,7 @@ def main():
     species3_primitiveVenturi.cfg_dir   = "../Tutorials/incompressible_flow/Inc_Species_Transport"
     species3_primitiveVenturi.cfg_file  = "species3_primitiveVenturi.cfg"
     species3_primitiveVenturi.test_iter = 50
-    species3_primitiveVenturi.test_vals = [-5.673011, -4.673114, -4.692686, -5.445043, -1.069650, -5.960206, -6.065010, 5.000000, -0.569992, 5.000000, -2.512966, 5.000000, -0.525813, 1.660601, 0.502277, 0.603346, 0.554977]
+    species3_primitiveVenturi.test_vals = [-5.679419, -4.675598, -4.699798, -5.463760, -1.072282, -5.965552, -6.075164, 5.000000, -0.558583, 5.000000, -2.514945, 5.000000, -0.514439, 1.660063, 0.502195, 0.603290, 0.554578]
     test_list.append(species3_primitiveVenturi)
 
     # 3 species (2 eq) primitive venturi mixing
@@ -144,7 +144,7 @@ def main():
     DAspecies3_primitiveVenturi.cfg_dir   = "../Tutorials/incompressible_flow/Inc_Species_Transport"
     DAspecies3_primitiveVenturi.cfg_file  = "DAspecies3_primitiveVenturi.cfg"
     DAspecies3_primitiveVenturi.test_iter = 50
-    DAspecies3_primitiveVenturi.test_vals = [-9.821887, -8.644118, -8.677534, -8.347228, -12.926295, -9.739487, -8.947991]
+    DAspecies3_primitiveVenturi.test_vals = [-9.806093, -8.630548, -8.666007, -8.333826, -12.914929, -11.064095, -10.278654]
     DAspecies3_primitiveVenturi.command   = TestCase.Command("mpirun -n 2", "SU2_CFD_AD")
     test_list.append(DAspecies3_primitiveVenturi)
 
@@ -165,7 +165,7 @@ def main():
     premixed_hydrogen.cfg_dir = "../Tutorials/incompressible_flow/Inc_Combustion/1__premixed_hydrogen"
     premixed_hydrogen.cfg_file = "H2_burner.cfg"
     premixed_hydrogen.test_iter = 10
-    premixed_hydrogen.test_vals = [-8.851285, -9.756885, -11.037752, -4.321598, -11.891933]
+    premixed_hydrogen.test_vals = [-9.647742, -10.286349, -11.353940, -4.380420, -12.831395]
     test_list.append(premixed_hydrogen)
 
     ### Compressible Flow

From 79ae023c45496d9e99fa3db8a1c7864dca73a835 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Mon, 5 Jan 2026 12:44:37 +0100
Subject: [PATCH 28/37] fix typo

---
 TestCases/tutorials.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/TestCases/tutorials.py b/TestCases/tutorials.py
index 3e88ce26e7a2..ee0d1976d2b9 100644
--- a/TestCases/tutorials.py
+++ b/TestCases/tutorials.py
@@ -89,7 +89,7 @@ def main():
     sp_pinArray_2d_dp_hf_tp.cfg_dir   = "../Tutorials/incompressible_flow/Inc_Streamwise_Periodic"
     sp_pinArray_2d_dp_hf_tp.cfg_file  = "sp_pinArray_2d_dp_hf_tp.cfg"
     sp_pinArray_2d_dp_hf_tp.test_iter = 25
-    sp_pinArray_2d_dp_hf_tp.test_vals = [-4.739709, -0.713547, 208.023676
+    sp_pinArray_2d_dp_hf_tp.test_vals = [-4.739709, -0.713547, 208.023676]
     sp_pinArray_2d_dp_hf_tp.test_vals_aarch64 = [-4.739709, -0.713547, 208.023676]
     test_list.append(sp_pinArray_2d_dp_hf_tp)
 

From dda4df01e6086289577fb97b00ea5e14c7124497 Mon Sep 17 00:00:00 2001
From: Nijso <bigfootedrockmidget@hotmail.com>
Date: Mon, 5 Jan 2026 13:21:35 +0100
Subject: [PATCH 29/37] Update SU2_CFD/src/solvers/CIncEulerSolver.cpp

---
 SU2_CFD/src/solvers/CIncEulerSolver.cpp | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/SU2_CFD/src/solvers/CIncEulerSolver.cpp b/SU2_CFD/src/solvers/CIncEulerSolver.cpp
index 0588dded4b1c..3646829bb1bb 100644
--- a/SU2_CFD/src/solvers/CIncEulerSolver.cpp
+++ b/SU2_CFD/src/solvers/CIncEulerSolver.cpp
@@ -383,14 +383,10 @@ void CIncEulerSolver::SetNondimensionalization(CConfig *config, unsigned short i
     Pressure_Ref    = 1.0;
   }
   else if (config->GetRef_Inc_NonDim() == INITIAL_VALUES) {
-    Density_Ref     = Density_FreeStream;
-    cout << "Density_Ref: " << Density_Ref << endl;
-    Velocity_Ref    = ModVel_FreeStream;
-    cout << "Velocity_Ref: " << Velocity_Ref << endl;
-    Temperature_Ref = Temperature_FreeStream;
-    cout << "Temperature_Ref: " << Temperature_Ref << endl;
-    Pressure_Ref    = Density_Ref*Velocity_Ref*Velocity_Ref;
-    cout << "Pressure_Ref: " << Pressure_Ref << endl;
+Density_Ref     = Density_FreeStream;
+Velocity_Ref    = ModVel_FreeStream;
+Temperature_Ref = Temperature_FreeStream;
+Pressure_Ref    = Density_Ref*Velocity_Ref*Velocity_Ref;
   }
   else if (config->GetRef_Inc_NonDim() == REFERENCE_VALUES) {
     Density_Ref     = config->GetInc_Density_Ref();

From a4d1264127a85edfd4c3a1332a4796cb6950a01b Mon Sep 17 00:00:00 2001
From: Nijso <bigfootedrockmidget@hotmail.com>
Date: Mon, 5 Jan 2026 13:43:41 +0100
Subject: [PATCH 30/37] Update SU2_CFD/src/solvers/CNSSolver.cpp

---
 SU2_CFD/src/solvers/CNSSolver.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/SU2_CFD/src/solvers/CNSSolver.cpp b/SU2_CFD/src/solvers/CNSSolver.cpp
index be79d762c7c8..f5dc3f95eda9 100644
--- a/SU2_CFD/src/solvers/CNSSolver.cpp
+++ b/SU2_CFD/src/solvers/CNSSolver.cpp
@@ -1037,7 +1037,7 @@ void CNSSolver::SetTau_Wall_WF(CGeometry *geometry, CSolver **solver_container,
 
         if (smallYPlusCounter)
           cout << "y+ < " << config->GetwallModel_MinYPlus() << " in " << smallYPlusCounter
-               << " points. No problem, but you can increase your near-wallmesh size." << endl;
+               << " points. No problem, but you can increase your near-wall mesh size." << endl;
       }
     }
     END_SU2_OMP_SAFE_GLOBAL_ACCESS

From b02ab50dab7c68c2f7b8a7b5422e55df266f0090 Mon Sep 17 00:00:00 2001
From: Nijso <bigfootedrockmidget@hotmail.com>
Date: Mon, 5 Jan 2026 13:43:51 +0100
Subject: [PATCH 31/37] Update
 TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg

---
 .../lam_prem_ch4_cht_ad_fluid.cfg                               | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg b/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg
index c7eada303242..9bd6a6aa2c90 100644
--- a/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg
+++ b/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg
@@ -21,7 +21,7 @@ HISTORY_OUTPUT= RMS_RES AERO_COEFF FLOW_COEFF FLOW_COEFF_SURF
 
 VOLUME_OUTPUT= SOLUTION PRIMITIVE SOURCE RESIDUAL LOOKUP
 
-OUTPUT_FILES= ( RESTART_ASCII, PARAVIEW)
+OUTPUT_FILES= ( RESTART_ASCII)
 
 WRT_RESTART_COMPACT= NO
 

From 67d511aa6541a04f46bca75ef314a5e15f4feef4 Mon Sep 17 00:00:00 2001
From: Nijso <bigfootedrockmidget@hotmail.com>
Date: Mon, 5 Jan 2026 13:44:21 +0100
Subject: [PATCH 32/37] Update
 TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_solid.cfg

---
 .../lam_prem_ch4_cht_ad_solid.cfg                               | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_solid.cfg b/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_solid.cfg
index 68ec9a5e6cab..99c48b1adade 100644
--- a/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_solid.cfg
+++ b/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_solid.cfg
@@ -7,7 +7,7 @@ MARKER_PLOTTING= ( NONE )
 MARKER_MONITORING= ( NONE )
 
 WRT_ZONE_HIST= YES
-OUTPUT_FILES= ( RESTART_ASCII, PARAVIEW )
+OUTPUT_FILES= ( RESTART_ASCII )
 
 INC_NONDIM= DIMENSIONAL
 

From bc0b1b0f74a18ae05dc2c3bb63f1d4a9269b8e4e Mon Sep 17 00:00:00 2001
From: Nijso <bigfootedrockmidget@hotmail.com>
Date: Mon, 5 Jan 2026 13:44:30 +0100
Subject: [PATCH 33/37] Update
 TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg

---
 .../lam_prem_ch4_cht_ad_fluid.cfg                             | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg b/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg
index 9bd6a6aa2c90..8b6b374d2046 100644
--- a/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg
+++ b/TestCases/flamelet/04_laminar_premixed_ch4_flame_cht_ad/lam_prem_ch4_cht_ad_fluid.cfg
@@ -59,8 +59,8 @@ FLUID_MODEL= FLUID_FLAMELET
 FILENAMES_INTERPOLATOR= (fgm_ch4.drg)
 CONTROLLING_VARIABLE_NAMES= (ProgressVariable, EnthalpyTot)
 CONTROLLING_VARIABLE_SOURCE_NAMES= (ProdRateTot_PV, NULL)
-FLAME_INIT_METHOD= FLAME_FRONT
-%FLAME_INIT_METHOD= NONE 
+%FLAME_INIT_METHOD= FLAME_FRONT
+FLAME_INIT_METHOD= NONE 
 FLAME_INIT= (0.004, 0.0, 0.0, 1, 0, 0, 0.2e-3, 1)
 
 % -------------------- SPECIES TRANSPORT ---------------------------------------%

From ebf0b074497df074ea4f0ef75b78730d186a9efc Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Mon, 5 Jan 2026 13:45:07 +0100
Subject: [PATCH 34/37] update some more regressions

---
 TestCases/parallel_regression.py    | 8 ++++----
 TestCases/parallel_regression_AD.py | 4 ++--
 TestCases/tutorials.py              | 2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/TestCases/parallel_regression.py b/TestCases/parallel_regression.py
index 4114f629dbaa..9b8dfafe8ec5 100755
--- a/TestCases/parallel_regression.py
+++ b/TestCases/parallel_regression.py
@@ -47,7 +47,7 @@ def main():
     cfd_flamelet_ch4.cfg_dir = "flamelet/01_laminar_premixed_ch4_flame_cfd"
     cfd_flamelet_ch4.cfg_file = "lam_prem_ch4_cfd.cfg"
     cfd_flamelet_ch4.test_iter = 10
-    cfd_flamelet_ch4.test_vals = [-14.971554, -15.910509, -9.042920, -16.513197, -19.488582, 104.940000]
+    cfd_flamelet_ch4.test_vals = [-14.429718, -15.860038, -8.226686, -16.506667, -19.493283, 87.326000]
     cfd_flamelet_ch4.new_output = True
     test_list.append(cfd_flamelet_ch4)
 
@@ -56,7 +56,7 @@ def main():
     cfd_flamelet_ch4_axi.cfg_dir = "flamelet/05_laminar_premixed_ch4_flame_cfd_axi"
     cfd_flamelet_ch4_axi.cfg_file = "lam_prem_ch4_cfd_axi.cfg"
     cfd_flamelet_ch4_axi.test_iter = 10
-    cfd_flamelet_ch4_axi.test_vals = [-11.259602, -10.020810, -11.852797, -4.909130, 95.000000]
+    cfd_flamelet_ch4_axi.test_vals = [-11.259626, -10.020810, -11.852795, -4.909152, 95.000000]
     cfd_flamelet_ch4_axi.new_output = True
     test_list.append(cfd_flamelet_ch4_axi)
 
@@ -65,7 +65,7 @@ def main():
     cfd_flamelet_ch4_partial_premix.cfg_dir = "flamelet/06_laminar_partial_premixed_ch4_flame_cfd"
     cfd_flamelet_ch4_partial_premix.cfg_file = "lam_partial_prem_ch4_cfd.cfg"
     cfd_flamelet_ch4_partial_premix.test_iter = 10
-    cfd_flamelet_ch4_partial_premix.test_vals = [-10.482722, -3.621023, -12.938151, -10.154391, 10.000000]
+    cfd_flamelet_ch4_partial_premix.test_vals = [-10.482722, -3.621055, -12.938151, -10.154391, 10.000000]
     cfd_flamelet_ch4_partial_premix.new_output = True
     test_list.append(cfd_flamelet_ch4_partial_premix)
 
@@ -1751,7 +1751,7 @@ def main():
     cfd_flamelet_ch4_cht.cfg_dir = "flamelet/03_laminar_premixed_ch4_flame_cht_cfd"
     cfd_flamelet_ch4_cht.cfg_file = "lam_prem_ch4_cht_cfd_master.cfg"
     cfd_flamelet_ch4_cht.test_iter = 5
-    cfd_flamelet_ch4_cht.test_vals = [-7.209184, -6.102044, -7.491447, -9.317122, -3.204897, -9.811662, -13.554684, -6.864880]
+    cfd_flamelet_ch4_cht.test_vals = [-9.824525, -8.913124, -9.862973, -11.271228, -3.238372, -10.916614, -12.615134, -6.614396]
     cfd_flamelet_ch4_cht.timeout = 1600
     cfd_flamelet_ch4_cht.multizone = True
     test_list.append(cfd_flamelet_ch4_cht)
diff --git a/TestCases/parallel_regression_AD.py b/TestCases/parallel_regression_AD.py
index 9dd012e0c995..bd309cd74fef 100644
--- a/TestCases/parallel_regression_AD.py
+++ b/TestCases/parallel_regression_AD.py
@@ -332,7 +332,7 @@ def main():
     discadj_flamelet_ch4_hx.cfg_file         = "lam_prem_ch4_hx_ad.cfg"
     discadj_flamelet_ch4_hx.multizone        = False
     discadj_flamelet_ch4_hx.test_iter        = 10
-    discadj_flamelet_ch4_hx.test_vals        = [-8.717448, -8.450564, -8.766800, -6.626764, -14.602479, -3.248656, -18.930954]
+    discadj_flamelet_ch4_hx.test_vals        = [-12.782056, -13.049168, -13.441039, -11.710302, -18.821992, -8.887596, -18.882447]
     test_list.append(discadj_flamelet_ch4_hx)
 
     # 2D planar laminar premixed flame on isothermal burner with conjugate heat transfer (restart)
@@ -341,7 +341,7 @@ def main():
     discadj_flamelet_ch4_cht.cfg_file         = "lam_prem_ch4_cht_ad_master.cfg"
     discadj_flamelet_ch4_cht.multizone        = True
     discadj_flamelet_ch4_cht.test_iter        = 10
-    discadj_flamelet_ch4_cht.test_vals        = [-2.764345, -1.998773, -2.082310, -0.140923, -7.287831, -18.655078, -18.622026, -4.847187]
+    discadj_flamelet_ch4_cht.test_vals        = [-1.543982, 0.628666, -6.533516, -18.651097, -18.648552, -3.794724, -6.561913, 11.000000]
     test_list.append(discadj_flamelet_ch4_cht)
 
     ######################################
diff --git a/TestCases/tutorials.py b/TestCases/tutorials.py
index ee0d1976d2b9..c15480eb3e32 100644
--- a/TestCases/tutorials.py
+++ b/TestCases/tutorials.py
@@ -165,7 +165,7 @@ def main():
     premixed_hydrogen.cfg_dir = "../Tutorials/incompressible_flow/Inc_Combustion/1__premixed_hydrogen"
     premixed_hydrogen.cfg_file = "H2_burner.cfg"
     premixed_hydrogen.test_iter = 10
-    premixed_hydrogen.test_vals = [-9.647742, -10.286349, -11.353940, -4.380420, -12.831395]
+    premixed_hydrogen.test_vals = [-9.647741, -10.286349, -11.353961, -4.380211, -12.831110]
     test_list.append(premixed_hydrogen)
 
     ### Compressible Flow

From 52d5353de4a09309adc42115b58f21d3dcebed24 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Tue, 6 Jan 2026 08:53:10 +0100
Subject: [PATCH 35/37] update some more regressions

---
 .../chtPinArray_2d/of_grad_findiff.csv.ref                    | 3 +--
 .../chtPinArray_2d/of_grad_findiff_aarch64.csv.ref            | 4 ++--
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff.csv.ref b/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff.csv.ref
index af480e5fa85c..a23afdd63e80 100644
--- a/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff.csv.ref
+++ b/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff.csv.ref
@@ -1,2 +1 @@
-"VARIABLE"      , "AVG_DENSITY[0]", "AVG_ENTHALPY[0]", "AVG_NORMALVEL[0]", "DRAG[0]"       , "EFFICIENCY[0]" , "FORCE_X[0]"    , "FORCE_Y[0]"    , "FORCE_Z[0]"    , "LIFT[0]"       , "MOMENT_X[0]"   , "MOMENT_Y[0]"   , "MOMENT_Z[0]"   , "SIDEFORCE[0]"  , "SURFACE_MACH[0]", "SURFACE_MASSFLOW[0]", "SURFACE_MOM_DISTORTION[0]", "SURFACE_PRESSURE_DROP[0]", "SURFACE_SECONDARY[0]", "SURFACE_SECOND_OVER_UNIFORM[0]", "SURFACE_STATIC_PRESSURE[0]", "SURFACE_STATIC_TEMPERATURE[0]", "SURFACE_TOTAL_PRESSURE[0]", "SURFACE_TOTAL_TEMPERATURE[0]", "SURFACE_UNIFORMITY[0]", "AVG_TEMPERATURE[1]", "TOTAL_HEATFLUX[1]", "FINDIFF_STEP"  
-0               , 0.0             , -409999.99619089067, -4.4410000000756306e-08, 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.12000000160217184, 3.3300000005652e-08, -0.2800000009628434      , 0.0                     , 1.1799999977135656  , 1.5699999966756195            , 2599.999999119973         , -119.99999287581886          , 3870.0000004610047       , -109.99999631167157         , 0.7999999995789153   , -210.00000174353772, 14480.000004368776, 1e-08           
+['"VARIABLE"      , "AVG_DENSITY[0]", "AVG_ENTHALPY[0]", "AVG_NORMALVEL[0]", "DRAG[0]"       , "EFFICIENCY[0]" , "FORCE_X[0]"    , "FORCE_Y[0]"    , "FORCE_Z[0]"    , "LIFT[0]"       , "MOMENT_X[0]"   , "MOMENT_Y[0]"   , "MOMENT_Z[0]"   , "SIDEFORCE[0]"  , "SURFACE_MACH[0]", "SURFACE_MASSFLOW[0]", "SURFACE_MOM_DISTORTION[0]", "SURFACE_PRESSURE_DROP[0]", "SURFACE_SECONDARY[0]", "SURFACE_SECOND_OVER_UNIFORM[0]", "SURFACE_STATIC_PRESSURE[0]", "SURFACE_STATIC_TEMPERATURE[0]", "SURFACE_TOTAL_PRESSURE[0]", "SURFACE_TOTAL_TEMPERATURE[0]", "SURFACE_UNIFORMITY[0]", "AVG_TEMPERATURE[1]", "TOTAL_HEATFLUX[1]", "FINDIFF_STEP"  \n', '0               , 0.0             , -20000.000949949026, 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , -0.01000000082740371, 1.1100000001884e-08, -0.04000000330961484     , 0.0                     , 0.01000000082740371 , 0.059999993862192014          , -9.999999406318238        , 0.0                          , -69.99999868639861       , 0.0                         , -0.09999998606957661 , -80.0000009348878 , -359.99998999614036, 1e-08           \n']
diff --git a/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff_aarch64.csv.ref b/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff_aarch64.csv.ref
index 711f20505853..af480e5fa85c 100644
--- a/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff_aarch64.csv.ref
+++ b/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff_aarch64.csv.ref
@@ -1,2 +1,2 @@
-"VARIABLE"      , "AVG_DENSITY[0]", "AVG_ENTHALPY[0]", "AVG_NORMALVEL[0]", "DRAG[0]"       , "EFFICIENCY[0]" , "FORCE_X[0]"    , "FORCE_Y[0]"    , "FORCE_Z[0]"    , "LIFT[0]"       , "MOMENT_X[0]"   , "MOMENT_Y[0]"   , "MOMENT_Z[0]"   , "SIDEFORCE[0]"  , "SURFACE_MACH[0]", "SURFACE_MASSFLOW[0]", "SURFACE_MOM_DISTORTION[0]", "SURFACE_PRESSURE_DROP[0]", "SURFACE_SECONDARY[0]", "SURFACE_SECOND_OVER_UNIFORM[0]", "SURFACE_STATIC_PRESSURE[0]", "SURFACE_STATIC_TEMPERATURE[0]", "SURFACE_TOTAL_PRESSURE[0]", "SURFACE_TOTAL_TEMPERATURE[0]", "SURFACE_UNIFORMITY[0]", "AVG_TEMPERATURE[1]", "TOTAL_HEATFLUX[1]", "FINDIFF_STEP"
-0               , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , -4.439999996617697e-08, 0.0                      , 0.0                     , 0.009999995276288587, 0.04000000330961484           , -9.999999406318238        , -20.000004496978363          , -49.999999873762135      , -19.99999312829459          , -0.09999998606957661 , -199.99999949504854, -369.9999979289714, 1e-08
+"VARIABLE"      , "AVG_DENSITY[0]", "AVG_ENTHALPY[0]", "AVG_NORMALVEL[0]", "DRAG[0]"       , "EFFICIENCY[0]" , "FORCE_X[0]"    , "FORCE_Y[0]"    , "FORCE_Z[0]"    , "LIFT[0]"       , "MOMENT_X[0]"   , "MOMENT_Y[0]"   , "MOMENT_Z[0]"   , "SIDEFORCE[0]"  , "SURFACE_MACH[0]", "SURFACE_MASSFLOW[0]", "SURFACE_MOM_DISTORTION[0]", "SURFACE_PRESSURE_DROP[0]", "SURFACE_SECONDARY[0]", "SURFACE_SECOND_OVER_UNIFORM[0]", "SURFACE_STATIC_PRESSURE[0]", "SURFACE_STATIC_TEMPERATURE[0]", "SURFACE_TOTAL_PRESSURE[0]", "SURFACE_TOTAL_TEMPERATURE[0]", "SURFACE_UNIFORMITY[0]", "AVG_TEMPERATURE[1]", "TOTAL_HEATFLUX[1]", "FINDIFF_STEP"  
+0               , 0.0             , -409999.99619089067, -4.4410000000756306e-08, 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.12000000160217184, 3.3300000005652e-08, -0.2800000009628434      , 0.0                     , 1.1799999977135656  , 1.5699999966756195            , 2599.999999119973         , -119.99999287581886          , 3870.0000004610047       , -109.99999631167157         , 0.7999999995789153   , -210.00000174353772, 14480.000004368776, 1e-08           

From 66e276793d9e26b90b22e34ce51005f52954f908 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Tue, 6 Jan 2026 09:51:04 +0100
Subject: [PATCH 36/37] update some more regressions

---
 .../streamwise_periodic/chtPinArray_2d/of_grad_findiff.csv.ref | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff.csv.ref b/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff.csv.ref
index a23afdd63e80..3e2b9a6332a8 100644
--- a/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff.csv.ref
+++ b/TestCases/incomp_navierstokes/streamwise_periodic/chtPinArray_2d/of_grad_findiff.csv.ref
@@ -1 +1,2 @@
-['"VARIABLE"      , "AVG_DENSITY[0]", "AVG_ENTHALPY[0]", "AVG_NORMALVEL[0]", "DRAG[0]"       , "EFFICIENCY[0]" , "FORCE_X[0]"    , "FORCE_Y[0]"    , "FORCE_Z[0]"    , "LIFT[0]"       , "MOMENT_X[0]"   , "MOMENT_Y[0]"   , "MOMENT_Z[0]"   , "SIDEFORCE[0]"  , "SURFACE_MACH[0]", "SURFACE_MASSFLOW[0]", "SURFACE_MOM_DISTORTION[0]", "SURFACE_PRESSURE_DROP[0]", "SURFACE_SECONDARY[0]", "SURFACE_SECOND_OVER_UNIFORM[0]", "SURFACE_STATIC_PRESSURE[0]", "SURFACE_STATIC_TEMPERATURE[0]", "SURFACE_TOTAL_PRESSURE[0]", "SURFACE_TOTAL_TEMPERATURE[0]", "SURFACE_UNIFORMITY[0]", "AVG_TEMPERATURE[1]", "TOTAL_HEATFLUX[1]", "FINDIFF_STEP"  \n', '0               , 0.0             , -20000.000949949026, 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , -0.01000000082740371, 1.1100000001884e-08, -0.04000000330961484     , 0.0                     , 0.01000000082740371 , 0.059999993862192014          , -9.999999406318238        , 0.0                          , -69.99999868639861       , 0.0                         , -0.09999998606957661 , -80.0000009348878 , -359.99998999614036, 1e-08           \n']
+"VARIABLE"      , "AVG_DENSITY[0]", "AVG_ENTHALPY[0]", "AVG_NORMALVEL[0]", "DRAG[0]"       , "EFFICIENCY[0]" , "FORCE_X[0]"    , "FORCE_Y[0]"    , "FORCE_Z[0]"    , "LIFT[0]"       , "MOMENT_X[0]"   , "MOMENT_Y[0]"   , "MOMENT_Z[0]"   , "SIDEFORCE[0]"  , "SURFACE_MACH[0]", "SURFACE_MASSFLOW[0]", "SURFACE_MOM_DISTORTION[0]", "SURFACE_PRESSURE_DROP[0]", "SURFACE_SECONDARY[0]", "SURFACE_SECOND_OVER_UNIFORM[0]", "SURFACE_STATIC_PRESSURE[0]", "SURFACE_STATIC_TEMPERATURE[0]", "SURFACE_TOTAL_PRESSURE[0]", "SURFACE_TOTAL_TEMPERATURE[0]", "SURFACE_UNIFORMITY[0]", "AVG_TEMPERATURE[1]", "TOTAL_HEATFLUX[1]", "FINDIFF_STEP"
+0               , 0.0             , -20000.000949949026, 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , 0.0             , -0.01000000082740371, 1.1100000001884e-08, -0.04000000330961484     , 0.0                     , 0.01000000082740371 , 0.059999993862192014          , -9.999999406318238        , 0.0                          , -69.99999868639861       , 0.0                         , -0.09999998606957661 , -80.0000009348878 , -359.99998999614036, 1e-08

From 370a9eb8f95a657d8b91ed5a6bc2b6f65d713a25 Mon Sep 17 00:00:00 2001
From: bigfooted <bigfootedrockmidget@hotmail.com>
Date: Tue, 6 Jan 2026 10:55:01 +0100
Subject: [PATCH 37/37] change regression back

---
 .github/workflows/regression.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/regression.yml b/.github/workflows/regression.yml
index c3d21e54c897..b7d4c3530d01 100644
--- a/.github/workflows/regression.yml
+++ b/.github/workflows/regression.yml
@@ -211,7 +211,7 @@ jobs:
         uses: docker://ghcr.io/su2code/su2/test-su2:250717-1402
         with:
           # -t <Tutorials-branch> -c <Testcases-branch>
-          args: -b ${{github.ref}} -t fix_enthalpy -c fix_enthalpy -s ${{matrix.testscript}}
+          args: -b ${{github.ref}} -t develop -c develop -s ${{matrix.testscript}}
       - name: Cleanup
         uses: docker://ghcr.io/su2code/su2/test-su2:250717-1402
         with: