Merge pull request #2323 from emaberman/SST_Var_Limit

Change lower limit of SST variables

Common/include/CConfig.hpp

@@ -878,6 +878,8 @@ class CConfig {
   ReThetaT_FreeStream,             /*!< \brief Freestream Transition Momentum Thickness Reynolds Number (for LM transition model) of the fluid.  */
   NuFactor_FreeStream,             /*!< \brief Ratio of turbulent to laminar viscosity. */
   NuFactor_Engine,                 /*!< \brief Ratio of turbulent to laminar viscosity at the engine. */
+  KFactor_LowerLimit,               /*!< \Non dimensional coefficient for lower limit of K in SST model. */
+  OmegaFactor_LowerLimit,           /*!< \Non dimensional coefficient for lower limit of omega in SST model. */
   SecondaryFlow_ActDisk,           /*!< \brief Ratio of turbulent to laminar viscosity at the actuator disk. */
   Initial_BCThrust,                /*!< \brief Ratio of turbulent to laminar viscosity at the actuator disk. */
   Pressure_FreeStream,             /*!< \brief Total pressure of the fluid. */
@@ -2008,6 +2010,18 @@ class CConfig {
    */
   su2double GetNuFactor_FreeStream(void) const { return NuFactor_FreeStream; }
 
+  /*!
+   * \brief Get the k constant factor define a lower limit by multiplication with values in SST turbulence model.
+   * \return Non-dimensionalized freestream intensity.
+   */
+  su2double GetKFactor_LowerLimit(void) const { return KFactor_LowerLimit; }
+
+  /*!
+    * \brief Get the w constant factor define a lower limit by multiplication with values in SST turbulencemodel.
+    * \return Non-dimensionalized freestream intensity.
+    */
+  su2double GetOmegaFactor_LowerLimit(void) const { return OmegaFactor_LowerLimit; }
+
   /*!
    * \brief Get the value of the non-dimensionalized engine turbulence intensity.
    * \return Non-dimensionalized engine intensity.

Common/include/option_structure.hpp

@@ -992,6 +992,7 @@ enum class SST_OPTIONS {
   UQ,          /*!< \brief Menter k-w SST model with uncertainty quantification modifications. */
   COMP_Wilcox, /*!< \brief Menter k-w SST model with Compressibility correction of Wilcox. */
   COMP_Sarkar, /*!< \brief Menter k-w SST model with Compressibility correction of Sarkar. */
+  DLL,         /*!< \brief Menter k-w SST model with dimensionless lower limit clipping of turbulence variables. */
 };
 static const MapType<std::string, SST_OPTIONS> SST_Options_Map = {
   MakePair("NONE", SST_OPTIONS::NONE)
@@ -1006,6 +1007,7 @@ static const MapType<std::string, SST_OPTIONS> SST_Options_Map = {
   MakePair("UQ", SST_OPTIONS::UQ)
   MakePair("COMPRESSIBILITY-WILCOX", SST_OPTIONS::COMP_Wilcox)
   MakePair("COMPRESSIBILITY-SARKAR", SST_OPTIONS::COMP_Sarkar)
+  MakePair("DIMENSIONLESS_LIMIT", SST_OPTIONS::DLL)
 };
 
 /*!
@@ -1019,6 +1021,7 @@ struct SST_ParsedOptions {
   bool modified = false;                      /*!< \brief Bool for modified (m) SST model. */
   bool compWilcox = false;                    /*!< \brief Bool for compressibility correction of Wilcox. */
   bool compSarkar = false;                    /*!< \brief Bool for compressibility correction of Sarkar. */
+  bool dll = false;                           /*!< \brief Bool dimensionless lower limit. */
 };
 
 /*!
@@ -1056,6 +1059,7 @@ inline SST_ParsedOptions ParseSSTOptions(const SST_OPTIONS *SST_Options, unsigne
   const bool sst_uq = IsPresent(SST_OPTIONS::UQ);
   const bool sst_compWilcox = IsPresent(SST_OPTIONS::COMP_Wilcox);
   const bool sst_compSarkar = IsPresent(SST_OPTIONS::COMP_Sarkar);
+  const bool sst_dll = IsPresent(SST_OPTIONS::DLL);
 
   if (sst_1994 && sst_2003) {
     SU2_MPI::Error("Two versions (1994 and 2003) selected for SST_OPTIONS. Please choose only one.", CURRENT_FUNCTION);
@@ -1090,6 +1094,8 @@ inline SST_ParsedOptions ParseSSTOptions(const SST_OPTIONS *SST_Options, unsigne
   SSTParsedOptions.uq = sst_uq;
   SSTParsedOptions.compWilcox = sst_compWilcox;
   SSTParsedOptions.compSarkar = sst_compSarkar;
+  SSTParsedOptions.dll = sst_dll;
+
   return SSTParsedOptions;
 }
 

Common/src/CConfig.cpp

@@ -1420,6 +1420,10 @@ void CConfig::SetConfig_Options() {
   /* DESCRIPTION:  */
   addDoubleOption("FREESTREAM_NU_FACTOR", NuFactor_FreeStream, 3.0);
   /* DESCRIPTION:  */
+  addDoubleOption("LOWER_LIMIT_K_FACTOR", KFactor_LowerLimit, 1.0e-15);
+  /* DESCRIPTION:  */
+  addDoubleOption("LOWER_LIMIT_OMEGA_FACTOR", OmegaFactor_LowerLimit, 1e-05);
+  /* DESCRIPTION:  */
   addDoubleOption("ENGINE_NU_FACTOR", NuFactor_Engine, 3.0);
   /* DESCRIPTION:  */
   addDoubleOption("ACTDISK_SECONDARY_FLOW", SecondaryFlow_ActDisk, 0.0);
@@ -6165,7 +6169,7 @@ void CConfig::SetOutput(SU2_COMPONENT val_software, unsigned short val_izone) {
             if (sstParsedOptions.version == SST_OPTIONS::V1994) cout << "-1994";
             else cout << "-2003";
             if (sstParsedOptions.modified) cout << "m";
-            if (sstParsedOptions.sust) cout << " with sustaining terms, and";
+            if (sstParsedOptions.sust) cout << " with sustaining terms,";
 
             switch (sstParsedOptions.production) {
               case SST_OPTIONS::KL:
@@ -6188,6 +6192,13 @@ void CConfig::SetOutput(SU2_COMPONENT val_software, unsigned short val_izone) {
                 cout << " with no production modification";
                 break;
             }
+
+            if (sstParsedOptions.dll){
+              cout << "\nusing non dimensional lower limits relative to infinity values clipping by Coefficients:" ;
+              cout << " C_w= " << OmegaFactor_LowerLimit << " and C_k= " <<KFactor_LowerLimit ;
+            }
+            else cout << "\nusing default hard coded lower limit clipping";
+
             cout << "." << endl;
             break;
         }

SU2_CFD/src/solvers/CTurbSSTSolver.cpp

@@ -97,7 +97,6 @@ CTurbSSTSolver::CTurbSSTSolver(CGeometry *geometry, CConfig *config, unsigned sh
   constants[5] = 0.0828; //beta_2
   constants[6] = 0.09;   //betaStar
   constants[7] = 0.31;   //a1
-
   if (sstParsedOptions.version == SST_OPTIONS::V1994){
     constants[8] = constants[4]/constants[6] - constants[2]*0.41*0.41/sqrt(constants[6]);  //alfa_1
     constants[9] = constants[5]/constants[6] - constants[3]*0.41*0.41/sqrt(constants[6]);  //alfa_2
@@ -108,12 +107,6 @@ CTurbSSTSolver::CTurbSSTSolver(CGeometry *geometry, CConfig *config, unsigned sh
     constants[9] = 0.44;  //gamma_2
     constants[10] = 10.0; // production limiter constant
   }
-  /*--- Initialize lower and upper limits---*/
-  lowerlimit[0] = 1.0e-10;
-  upperlimit[0] = 1.0e10;
-
-  lowerlimit[1] = 1.0e-4;
-  upperlimit[1] = 1.0e15;
 
   /*--- Far-field flow state quantities and initialization. ---*/
   su2double rhoInf, *VelInf, muLamInf, Intensity, viscRatio, muT_Inf;
@@ -132,6 +125,22 @@ CTurbSSTSolver::CTurbSSTSolver(CGeometry *geometry, CConfig *config, unsigned sh
   Solution_Inf[0] = kine_Inf;
   Solution_Inf[1] = omega_Inf;
 
+  /*--- Constants to use for lower limit of turbulence variable. ---*/
+  su2double Ck = config->GetKFactor_LowerLimit();
+  su2double Cw = config->GetOmegaFactor_LowerLimit();
+
+  /*--- Initialize lower and upper limits. ---*/
+  if (sstParsedOptions.dll) {
+    lowerlimit[0] = Ck * kine_Inf;
+    lowerlimit[1] = Cw * omega_Inf;
+  } else {
+    lowerlimit[0] = 1.0e-10;
+    lowerlimit[1] = 1.0e-4;
+  }
+
+  upperlimit[0] = 1.0e10;
+  upperlimit[1] = 1.0e15;
+
   /*--- Eddy viscosity, initialized without stress limiter at the infinity ---*/
   muT_Inf = rhoInf*kine_Inf/omega_Inf;
 

config_template.cfg

@@ -21,7 +21,7 @@ SOLVER= EULER
 % Specify turbulence model (NONE, SA, SST)
 KIND_TURB_MODEL= NONE
 %
-% Specify versions/corrections of the SST model (V2003m, V1994m, VORTICITY, KATO_LAUNDER, UQ, SUSTAINING, COMPRESSIBILITY-WILCOX, COMPRESSIBILITY-SARKAR)
+% Specify versions/corrections of the SST model (V2003m, V1994m, VORTICITY, KATO_LAUNDER, UQ, SUSTAINING, COMPRESSIBILITY-WILCOX, COMPRESSIBILITY-SARKAR, DIMENSIONLESS_LIMIT)
 SST_OPTIONS= NONE
 %
 % Specify versions/corrections of the SA model (NEGATIVE, EDWARDS, WITHFT2, QCR2000, COMPRESSIBILITY, ROTATION, BCM, EXPERIMENTAL)
@@ -1801,6 +1801,10 @@ TIME_DISCRE_TURB= EULER_IMPLICIT
 % Reduction factor of the CFL coefficient in the turbulence problem
 CFL_REDUCTION_TURB= 1.0
 
+% Control lower limit constants of the SST model (C*phi_infinity)
+LOWER_LIMIT_K_FACTOR= 1e-15
+LOWER_LIMIT_OMEGA_FACTOR= 1e-5
+
 % --------------------- HEAT NUMERICAL METHOD DEFINITION ----------------------%
 %
 % Value of the thermal diffusivity