fix: Address reviewer feedback on wall model bug fixes

Wall model (wall_model.cpp):
- Use fmax(x, 1e-16) in denominator for convergence check
- Use fmin(Gamma, -1e-16) in exp denominator (Gamma is always negative)

Reverted changes per reviewer request:
- CPhysicalGeometry.cpp: Revert to original strcpy (don't complicate)
- CSolver.cpp: Revert ITER offset to 9 (original author had reason)
- CRadP1Solver.cpp: Remove emissivity validation (should be in CConfig)

Signed-off-by: shbhmexe <[email protected]>

Author: shbhmexe

Common/src/geometry/CPhysicalGeometry.cpp

@@ -8252,8 +8252,7 @@ void CPhysicalGeometry::SetSensitivity(CConfig* config) {
 
     char str_buf[CGNS_STRING_SIZE], fname[100];
     unsigned short iVar;
-    strncpy(fname, filename.c_str(), sizeof(fname) - 1);
-    fname[sizeof(fname) - 1] = '\0';  // Ensure null termination
+    strcpy(fname, filename.c_str());
     int nRestart_Vars = 5, nFields;
     int* Restart_Vars = new int[5];
     passivedouble* Restart_Data = nullptr;
@@ -8566,8 +8565,7 @@ void CPhysicalGeometry::SetSensitivity(CConfig* config) {
     /*--- First, check that this is not a binary restart file. ---*/
 
     char fname[100];
-    strncpy(fname, filename.c_str(), sizeof(fname) - 1);
-    fname[sizeof(fname) - 1] = '\0';  // Ensure null termination
+    strcpy(fname, filename.c_str());
     int magic_number;
 
 #ifndef HAVE_MPI

Common/src/wall_model.cpp

@@ -306,11 +306,9 @@ void CWallModel1DEQ::WallShearStressAndHeatFlux(const su2double tExchange, const
     if (y_cv[0] * sqrt(tauWall / rho) / (mu_lam / rho) > 1.0)
       SU2_MPI::Error("Y+ greater than one: Increase the number of points or growth ratio.", CURRENT_FUNCTION);
 
-    /* Define a norm
-     * Check convergence only if previous values are non-zero to avoid division by zero
-     */
-    bool tau_converged = (tauWall_prev != 0.0) ? (abs(1.0 - tauWall / tauWall_prev) < tol) : false;
-    bool q_converged = (qWall_prev != 0.0) ? (abs(1.0 - qWall / qWall_prev) < tol) : false;
+    /* Define a norm */
+    bool tau_converged = abs(1.0 - tauWall / fmax(tauWall_prev, 1e-16)) < tol;
+    bool q_converged = abs(1.0 - qWall / fmax(qWall_prev, 1e-16)) < tol;
 
     if (tau_converged && q_converged) {
       converged = true;
@@ -394,20 +392,9 @@ void CWallModelLogLaw::WallShearStressAndHeatFlux(const su2double tExchange, con
     const su2double lhs = -((tExchange - TWall) * rho_wall * c_p * u_tau);
     const su2double Gamma = -(0.01 * (Pr_lam * pow(y_plus, 4.0)) / (1.0 + 5.0 * y_plus * pow(Pr_lam, 3.0)));
     const su2double rhs_1 = Pr_lam * y_plus * exp(Gamma);
-    
-    /* Protect against division by zero in exp(1/Gamma) when Gamma is very small */
-    const su2double eps_gamma = 1e-20;
-    su2double exp_term;
-    if (abs(Gamma) > eps_gamma) {
-      exp_term = exp(1.0 / Gamma);
-    } else {
-      /* For very small Gamma, cap the exponential to prevent overflow/division by zero */
-      exp_term = (Gamma > 0) ? exp(1.0 / eps_gamma) : exp(-1.0 / eps_gamma);
-    }
-    
     const su2double rhs_2 =
         (2.12 * log(1.0 + y_plus) + pow((3.85 * pow(Pr_lam, (1.0 / 3.0)) - 1.3), 2.0) + 2.12 * log(Pr_lam)) *
-        exp_term;
+        exp(1.0 / fmin(Gamma, -1e-16));
     qWall = lhs / (rhs_1 + rhs_2);
   } else {
     qWall = Wall_HeatFlux;

SU2_CFD/src/solvers/CRadP1Solver.cpp

@@ -282,18 +282,10 @@ void CRadP1Solver::BC_Isothermal_Wall(CGeometry *geometry, CSolver **solver_cont
   /*--- Get the specified wall emissivity from config ---*/
   Wall_Emissivity = config->GetWall_Emissivity(Marker_Tag);
 
-  /*--- Clamp emissivity to valid physical range [0,1] to prevent division by zero ---*/
-  if (Wall_Emissivity < 0.0) {
-    Wall_Emissivity = 0.0;
-  }
-  if (Wall_Emissivity > 1.0) {
-    Wall_Emissivity = 1.0;
-  }
-
   /*--- Compute the constant for the wall theta ---*/
   Theta = Wall_Emissivity / (2.0*(2.0 - Wall_Emissivity));
 
-    /*--- Retrieve the specified wall temperature ---*/
+  /*--- Retrieve the specified wall temperature ---*/
   Twall = config->GetIsothermal_Temperature(Marker_Tag)/config->GetTemperature_Ref();
 
   /*--- Loop over all of the vertices on this boundary marker ---*/
@@ -364,14 +356,6 @@ void CRadP1Solver::BC_Far_Field(CGeometry *geometry, CSolver **solver_container,
   /*--- Get the specified wall emissivity from config ---*/
   Wall_Emissivity = config->GetWall_Emissivity(Marker_Tag);
 
-  /*--- Clamp emissivity to valid physical range [0,1] to prevent division by zero ---*/
-  if (Wall_Emissivity < 0.0) {
-    Wall_Emissivity = 0.0;
-  }
-  if (Wall_Emissivity > 1.0) {
-    Wall_Emissivity = 1.0;
-  }
-
   /*--- Compute the constant for the wall theta ---*/
   Theta = Wall_Emissivity / (2.0*(2.0 - Wall_Emissivity));
 
@@ -446,19 +430,6 @@ void CRadP1Solver::BC_Marshak(CGeometry *geometry, CSolver **solver_container, C
   /*--- Get the specified wall emissivity from config ---*/
   Wall_Emissivity = config->GetWall_Emissivity(Marker_Tag);
 
-  /*--- Clamp emissivity to valid physical range [0,1] to prevent division by zero ---*/
-<<<<<<< HEAD
-  if (Wall_Emissivity < 0.0) {
-    Wall_Emissivity = 0.0;
-  }
-  if (Wall_Emissivity > 1.0) {
-    Wall_Emissivity = 1.0;
-  }
-=======
-  if (Wall_Emissivity < 0.0) Wall_Emissivity = 0.0;
-  if (Wall_Emissivity > 1.0) Wall_Emissivity = 1.0;
->>>>>>> 46baac1286ba393e261fef83bced67d0d4d3f269
-
   /*--- Compute the constant for the wall theta ---*/
   Theta = Wall_Emissivity / (2.0*(2.0 - Wall_Emissivity));
 

SU2_CFD/src/solvers/CSolver.cpp

@@ -3381,10 +3381,9 @@ void CSolver::Read_SU2_Restart_Metadata(CGeometry *geometry, CConfig *config, bo
 
       /*--- External iteration ---*/
 
-      position = text_line.find("ITER=", 0);
+      position = text_line.find ("ITER=",0);
       if (position != string::npos) {
-        text_line.erase(0, 5);
-        InnerIter_ = atoi(text_line.c_str());  // 'ITER=' has 5 chars
+        text_line.erase (0,9); InnerIter_ = atoi(text_line.c_str());
       }
 
       /*--- Angle of attack ---*/