Implementation of Simplified LM Transition model

Common/include/geometry/dual_grid/CPoint.hpp

@@ -456,6 +456,18 @@ class CPoint {
   }
   inline void SetWall_Distance(unsigned long iPoint, su2double distance) { Wall_Distance(iPoint) = distance; }
 
+  /*!
+   * \brief Get the index of the closest wall element.
+   * \param[in] iPoint - Index of the point.
+   */
+  inline unsigned long GetClosestWall_Elem(unsigned long iPoint) {return ClosestWall_Elem(iPoint);}
+
+  /*!
+   * \brief Get the marker of the closest wall marker.
+   * \param[in] iPoint - Index of the point.
+   */
+  inline unsigned long GetClosestWall_Marker(unsigned long iPoint) {return ClosestWall_Marker(iPoint);}
+
   /*!
    * \brief Get the value of the distance to the nearest wall.
    * \param[in] iPoint - Index of the point.

Common/include/option_structure.hpp

@@ -1173,26 +1173,36 @@ static const MapType<std::string, TURB_TRANS_MODEL> Trans_Model_Map = {
  */
 enum class LM_OPTIONS {
   NONE,         /*!< \brief No option / default. */
-  LM2015,       /*!< \brief Cross-flow corrections. */
+  CROSSFLOW,    /*!< \brief Cross-flow corrections. */
+  SLM,          /*!< \brief Simplified version. */
+  PRODLIM,      /*!< \brief Add production term to Pk. */
   MALAN,        /*!< \brief Kind of transition correlation model (Malan). */
   SULUKSNA,     /*!< \brief Kind of transition correlation model (Suluksna). */
   KRAUSE,       /*!< \brief Kind of transition correlation model (Krause). */
   KRAUSE_HYPER, /*!< \brief Kind of transition correlation model (Krause hypersonic). */
   MEDIDA_BAEDER,/*!< \brief Kind of transition correlation model (Medida-Baeder). */
   MEDIDA,       /*!< \brief Kind of transition correlation model (Medida). */
   MENTER_LANGTRY,   /*!< \brief Kind of transition correlation model (Menter-Langtry). */
+  MENTER_SLM,   /*!< \brief Kind of transition correlation model (Menter Simplified LM model). */
+  CODER_SLM,   /*!< \brief Kind of transition correlation model (Coder Simplified LM model). */
+  MOD_EPPLER_SLM,        /*!< \brief Kind of transition correlation model (Modified Eppler Simplified LM model). */
   DEFAULT       /*!< \brief Kind of transition correlation model (Menter-Langtry if SST, MALAN if SA). */
 };
 
 static const MapType<std::string, LM_OPTIONS> LM_Options_Map = {
   MakePair("NONE", LM_OPTIONS::NONE)
-  MakePair("LM2015", LM_OPTIONS::LM2015)
+  MakePair("CROSSFLOW", LM_OPTIONS::CROSSFLOW)
+  MakePair("SLM", LM_OPTIONS::SLM)
+  MakePair("PRODLIM", LM_OPTIONS::PRODLIM)
   MakePair("MALAN", LM_OPTIONS::MALAN)
   MakePair("SULUKSNA", LM_OPTIONS::SULUKSNA)
   MakePair("KRAUSE", LM_OPTIONS::KRAUSE)
   MakePair("KRAUSE_HYPER", LM_OPTIONS::KRAUSE_HYPER)
   MakePair("MEDIDA_BAEDER", LM_OPTIONS::MEDIDA_BAEDER)
   MakePair("MENTER_LANGTRY", LM_OPTIONS::MENTER_LANGTRY)
+  MakePair("MENTER_SLM", LM_OPTIONS::MENTER_SLM)
+  MakePair("CODER_SLM", LM_OPTIONS::CODER_SLM)
+  MakePair("MOD_EPPLER_SLM", LM_OPTIONS::MOD_EPPLER_SLM)
   MakePair("DEFAULT", LM_OPTIONS::DEFAULT)
 };
 
@@ -1210,13 +1220,26 @@ enum class TURB_TRANS_CORRELATION {
   DEFAULT       /*!< \brief Kind of transition correlation model (Menter-Langtry if SST, MALAN if SA). */
 };
 
+/*!
+ * \brief Types of transition correlations for Simplified LM model
+ */
+enum class TURB_TRANS_CORRELATION_SLM {
+  MENTER_SLM,        /*!< \brief Kind of transition correlation model (Menter Simplified LM model). */
+  CODER_SLM,        /*!< \brief Kind of transition correlation model (Coder Simplified LM model). */
+  MOD_EPPLER_SLM,        /*!< \brief Kind of transition correlation model (Modified Eppler Simplified LM model). */
+  DEFAULT       /*!< \brief Kind of transition correlation model. */
+};
+
 /*!
  * \brief Structure containing parsed LM options.
  */
 struct LM_ParsedOptions {
   LM_OPTIONS version = LM_OPTIONS::NONE;  /*!< \brief LM base model. */
-  bool LM2015 = false;                    /*!< \brief Use cross-flow corrections. */
+  bool CrossFlow = false;                 /*!< \brief Use cross-flow corrections. */
+  bool SLM = false;                       /*!< \brief Use simplified version. */
+  bool ProdLim = false;                   /*!< \brief Add production term to Pk. */
   TURB_TRANS_CORRELATION Correlation = TURB_TRANS_CORRELATION::DEFAULT;
+  TURB_TRANS_CORRELATION_SLM Correlation_SLM = TURB_TRANS_CORRELATION_SLM::DEFAULT;
 };
 
 /*!
@@ -1234,9 +1257,12 @@ inline LM_ParsedOptions ParseLMOptions(const LM_OPTIONS *LM_Options, unsigned sh
     return std::find(LM_Options, lm_options_end, option) != lm_options_end;
   };
 
-  LMParsedOptions.LM2015 = IsPresent(LM_OPTIONS::LM2015);
+  LMParsedOptions.CrossFlow = IsPresent(LM_OPTIONS::CROSSFLOW);
+  LMParsedOptions.SLM = IsPresent(LM_OPTIONS::SLM);
+  LMParsedOptions.ProdLim = IsPresent(LM_OPTIONS::PRODLIM);
 
   int NFoundCorrelations = 0;
+  int NFoundCorrelations_SLM = 0;
   if (IsPresent(LM_OPTIONS::MALAN)) {
     LMParsedOptions.Correlation = TURB_TRANS_CORRELATION::MALAN;
     NFoundCorrelations++;
@@ -1265,10 +1291,25 @@ inline LM_ParsedOptions ParseLMOptions(const LM_OPTIONS *LM_Options, unsigned sh
     LMParsedOptions.Correlation = TURB_TRANS_CORRELATION::MENTER_LANGTRY;
     NFoundCorrelations++;
   }
+  if (IsPresent(LM_OPTIONS::MENTER_SLM)) {
+    LMParsedOptions.Correlation_SLM = TURB_TRANS_CORRELATION_SLM::MENTER_SLM;
+    NFoundCorrelations_SLM++;
+  }
+  if (IsPresent(LM_OPTIONS::CODER_SLM)) {
+    LMParsedOptions.Correlation_SLM = TURB_TRANS_CORRELATION_SLM::CODER_SLM;
+    NFoundCorrelations_SLM++;
+  }
+  if (IsPresent(LM_OPTIONS::MOD_EPPLER_SLM)) {
+    LMParsedOptions.Correlation_SLM = TURB_TRANS_CORRELATION_SLM::MOD_EPPLER_SLM;
+    NFoundCorrelations_SLM++;
+  }
 
   if (NFoundCorrelations > 1) {
     SU2_MPI::Error("Two correlations selected for LM_OPTIONS. Please choose only one.", CURRENT_FUNCTION);
   }
+  if (NFoundCorrelations_SLM > 1) {
+    SU2_MPI::Error("Two correlations selected for Simplified model into LM_OPTIONS. Please choose only one.", CURRENT_FUNCTION);
+  }
 
   if (LMParsedOptions.Correlation == TURB_TRANS_CORRELATION::DEFAULT){
     if (Kind_Turb_Model == TURB_MODEL::SST) {
@@ -1278,6 +1319,10 @@ inline LM_ParsedOptions ParseLMOptions(const LM_OPTIONS *LM_Options, unsigned sh
     }
   }
 
+  if (LMParsedOptions.Correlation_SLM == TURB_TRANS_CORRELATION_SLM::DEFAULT){
+    LMParsedOptions.Correlation_SLM = TURB_TRANS_CORRELATION_SLM::MENTER_SLM;
+  }
+
   return LMParsedOptions;
 }
 

Common/src/CConfig.cpp

@@ -3471,9 +3471,9 @@ void CConfig::SetPostprocessing(SU2_COMPONENT val_software, unsigned short val_i
   if (Kind_Trans_Model == TURB_TRANS_MODEL::LM) {
     lmParsedOptions = ParseLMOptions(LM_Options, nLM_Options, rank, Kind_Turb_Model);
 
-    /*--- Check if problem is 2D and LM2015 has been selected ---*/
-    if (lmParsedOptions.LM2015 && val_nDim == 2) {
-      SU2_MPI::Error("LM2015 is available only for 3D problems", CURRENT_FUNCTION);
+    /*--- Check if problem is 2D and CrossFlow has been selected ---*/
+    if (lmParsedOptions.CrossFlow && val_nDim == 2) {
+      SU2_MPI::Error("Cross-flow corrections are available only for 3D problems", CURRENT_FUNCTION);
     }
   }
 
@@ -6113,11 +6113,27 @@ void CConfig::SetOutput(SU2_COMPONENT val_software, unsigned short val_izone) {
         switch (Kind_Trans_Model) {
           case TURB_TRANS_MODEL::NONE:  break;
           case TURB_TRANS_MODEL::LM: {
-            cout << "Transition model: Langtry and Menter's 4 equation model";
-            if (lmParsedOptions.LM2015) {
-              cout << " w/ cross-flow corrections (2015)" << endl;
+            int NTurbEqs = 0;
+            switch (Kind_Turb_Model) {
+              case TURB_MODEL::SA: NTurbEqs = 1;  break;
+              case TURB_MODEL::SST: NTurbEqs = 2;  break;
+              case TURB_MODEL::NONE: SU2_MPI::Error("No turbulence model has been selected but LM transition model is active.", CURRENT_FUNCTION); break;
+            }
+            if (!lmParsedOptions.SLM) {
+              int NEquations = 2;
+              cout << "Transition model: Langtry and Menter's "<< NEquations+NTurbEqs <<" equation model";
             } else {
-              cout << " (2009)" << endl;
+              int NEquations = 1;
+              cout << "Transition model: Simplified Langtry and Menter's "<< NEquations+NTurbEqs <<" equation model";
+            }
+            if (lmParsedOptions.CrossFlow) {
+              cout << " w/ cross-flow corrections" << endl;
+            } else {
+              if (!lmParsedOptions.SLM) {
+                cout << " (2009)" << endl;
+              } else {
+                cout << " (2015)" << endl;
+              }
             }
             break;
           }
@@ -6141,6 +6157,13 @@ void CConfig::SetOutput(SU2_COMPONENT val_software, unsigned short val_izone) {
               }
               break;
           }
+          cout << "Correlation Functions for Simplified LM model: ";
+          switch (lmParsedOptions.Correlation_SLM) {
+            case TURB_TRANS_CORRELATION_SLM::CODER_SLM: cout << "Coder et al. (2012)" << endl;  break;
+            case TURB_TRANS_CORRELATION_SLM::MOD_EPPLER_SLM: cout << "Modified Eppler (from Coder et al. 2012)" << endl;  break;
+            case TURB_TRANS_CORRELATION_SLM::MENTER_SLM:
+            case TURB_TRANS_CORRELATION_SLM::DEFAULT: cout << "Menter et al. (2015)" << endl;  break;
+          }
         }
         cout << "Hybrid RANS/LES: ";
         switch (Kind_HybridRANSLES) {

SU2_CFD/include/numerics/CNumerics.hpp

@@ -734,6 +734,25 @@ class CNumerics {
    */
   su2double GetIntermittencyEff() const { return intermittency_eff_i; }
 
+  /*!
+   * \brief Get the value of the Transition Momentum Thickness Reynolds number from correlations.
+   * \param[in] Corr_Rec_i - Value of the Transition Momentum Thickness Reynolds number at point i.
+   */
+  inline virtual su2double GetCorr_Rec() {return 0.0;}
+
+   /*!
+   * \brief Get the value of the Momentum Thickness Reynolds number.
+   * \param[in] Corr_Rec_i - Value of the Momentum Thickness Reynolds number at point i.
+   */
+  inline virtual su2double GetRe_t() {return 0.0;}
+
+  /*!
+   * \brief Set the gradient of the auxiliary variables.
+   * \param[in] val_auxvar_grad_i - Gradient of the auxiliary variable at point i.
+   * \param[in] val_auxvar_grad_j - Gradient of the auxiliary variable at point j.
+   */
+  inline virtual void SetAuxVar(su2double val_AuxVar) {}
+
   /*!
    * \brief Set the gradient of the auxiliary variables.
    * \param[in] val_auxvar_grad_i - Gradient of the auxiliary variable at point i.

SU2_CFD/include/numerics/turbulent/transition/trans_convection.hpp

@@ -38,3 +38,10 @@
 template <class FlowIndices>
 using CUpwSca_TransLM  = CUpwSca_TurbSST<FlowIndices>;
 
+/*!
+ * \class CUpwSca_TransSLM
+ * \brief Re-use the SA convective fluxes for the scalar upwind discretization of Simplified LM transition model equations.
+ * \ingroup ConvDiscr
+ */
+template <class FlowIndices>
+using CUpwSca_TransSLM  = CUpwSca_TurbSA<FlowIndices>;

SU2_CFD/include/numerics/turbulent/transition/trans_correlations.hpp

@@ -25,6 +25,7 @@
  */
 
 #pragma once
+//#include <cmath>
 
 /*!
  * \class TransLMCorrelations
@@ -189,4 +190,107 @@ class TransLMCorrelations {
 
     return F_length1;
   }
+
+  /*!
+   * \brief Compute Re_theta_c from correlations for the Simplified LM model.
+   * \param[in] Tu - Turbulence intensity.
+   * \param[in] du_ds - Streamwise velocity gradient.
+   * \param[out] rethetac - Corrected value for Re_theta.
+   */
+  su2double ReThetaC_Correlations_SLM(const su2double Tu_L, const su2double lambda_theta, const su2double wall_dist, const su2double VorticityMag, const su2double VelocityMag) const {
+
+    su2double rethetac = 0.0;
+
+    switch (options.Correlation_SLM) {
+      case TURB_TRANS_CORRELATION_SLM::MENTER_SLM: {
+
+        /*-- Thwaites parameter ---*/
+        // su2double  lambda_theta_local = 7.57e-3 * du_ds * wall_dist * wall_dist * Density / Laminar_Viscosity + 0.0128;
+        su2double  lambda_theta_local = lambda_theta;
+        lambda_theta_local = min(max(lambda_theta_local, -1.0), 1.0);
+
+        /*-- Function to sensitize the transition onset to the streamwise pressure gradient ---*/
+        su2double FPG = 0.0;
+        const su2double C_PG1 = 14.68;
+        const su2double C_PG1_lim = 1.5;
+        const su2double C_PG2 = -7.34;
+        const su2double C_PG2_lim = 3.0;
+        const su2double C_PG3 = 0.0;
+        if (lambda_theta_local >= 0.0) {
+          FPG = min(1+ C_PG1 * lambda_theta_local, C_PG1_lim);
+        } else {
+          const su2double FirstTerm = C_PG2 * lambda_theta_local;
+          const su2double SecondTerm = C_PG3 * min(lambda_theta_local + 0.0681, 0.0);
+          FPG = min(1 + FirstTerm + SecondTerm, C_PG2_lim);
+        }
+
+        FPG = max(FPG, 0.0);
+
+        const su2double C_TU1 = 100.0;
+        const su2double C_TU2 = 1000.0;
+        const su2double C_TU3 = 1.0;
+        rethetac = C_TU1 + C_TU2 * exp(-C_TU3 * Tu_L * FPG);
+
+        break;
+      } case TURB_TRANS_CORRELATION_SLM::CODER_SLM: {
+
+        /*-- Local pressure gradient parameter ---*/
+        const su2double H_c = max(min(wall_dist * VorticityMag / VelocityMag, 1.1542), 0.3823);
+
+        /*-- Thwaites parameter ---*/
+        su2double lambda_theta_local = 0.0;
+        const su2double H_c_delta = 0.587743 - H_c;
+        if ( H_c >= 0.587743 ) {
+          const su2double FirstTerm = 0.1919 * pow(H_c_delta, 3.0);
+          const su2double SecondTerm = 0.4182 * pow(H_c_delta, 2.0);
+          const su2double ThirdTerm = 0.2959 * H_c_delta;
+          lambda_theta_local = FirstTerm + SecondTerm + ThirdTerm;
+        } else {
+          const su2double FirstTerm = 4.7596 * pow(H_c_delta, 3.0);
+          const su2double SecondTerm = -0.3837 * pow(H_c_delta, 2.0);
+          const su2double ThirdTerm = 0.3575 * H_c_delta;
+          lambda_theta_local = FirstTerm + SecondTerm + ThirdTerm;
+        }
+
+        /*-- Function to sensitize the transition onset to the streamwise pressure gradient ---*/
+        su2double FPG = 0.0;
+        if (lambda_theta_local <= 0.0) {
+          const su2double FirstTerm = -12.986 * lambda_theta_local;
+          const su2double SecondTerm = -123.66 * pow(lambda_theta_local, 2.0);
+          const su2double ThirdTerm = -405.689 * pow(lambda_theta_local, 3.0);
+          FPG = 1 - (FirstTerm + SecondTerm + ThirdTerm) * exp(-pow(Tu_L/1.5,1.5));
+        } else {
+          FPG = 1 + 0.275 * (1 - exp(-35.0 * lambda_theta_local)) * exp(-Tu_L/0.5);
+        }
+
+        // This is not reported in the paper
+        //FPG = max(FPG, 0.0);
+
+        const su2double C_TU1 = 100.0;
+        const su2double C_TU2 = 1000.0;
+        const su2double C_TU3 = 1.0;
+        rethetac = C_TU1 + C_TU2 * exp(-C_TU3 * Tu_L * FPG);
+
+        break;
+      } case TURB_TRANS_CORRELATION_SLM::MOD_EPPLER_SLM: {
+
+        /*-- Local pressure gradient parameter ---*/
+        const su2double H_c = max(min(wall_dist * VorticityMag / VelocityMag, 1.1542), 0.3823);
+
+        /*-- H_32 Shape factor --*/
+        const su2double H_32 = 1.515095 + 0.2041 * pow((1.1542 - H_c), 2.0956);
+
+        rethetac = exp(127.94 * pow((H_32-1.515095), 2.0) + 6.774224);
+
+        break;
+      }
+      case TURB_TRANS_CORRELATION_SLM::DEFAULT:
+        SU2_MPI::Error("Transition correlation for Simplified LM model is set to DEFAULT but no default value has ben set in the code.",
+                       CURRENT_FUNCTION);
+        break;
+    }
+
+    return rethetac;
+  }
+
 };