Feature new flamelet: addition of preferential diffusion

.github/workflows/regression.yml

@@ -171,7 +171,7 @@ jobs:
         uses: docker://ghcr.io/su2code/su2/test-su2:230813-0103
         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 feature_new_flamelet -s ${{matrix.testscript}}
       - name: Cleanup
         uses: docker://ghcr.io/su2code/su2/test-su2:230813-0103
         with:

Common/include/CConfig.hpp

@@ -1224,7 +1224,12 @@ class CConfig {
   unsigned short nSpecies_Init;    /*!< \brief Number of entries of SPECIES_INIT */
 
   /*--- Additional flamelet solver options ---*/
-  su2double flame_init[8];       /*!< \brief Initial solution parameters for flamelet solver.*/
+  FLAMELET_INIT_TYPE flame_init_type = FLAMELET_INIT_TYPE::NONE; /*!< \brief Method for solution ignition for flamelet problems. */
+  su2double flame_init[8];       /*!< \brief Flame front initialization parameters. */
+  su2double spark_init[6];       /*!< \brief Spark ignition initialization parameters. */
+  su2double* spark_reaction_rates; /*!< \brief Source terms for flamelet spark ignition option. */
+  unsigned short nspark;           /*!< \brief Number of source terms for spark initialization. */
+  bool preferential_diffusion = false;  /*!< \brief Preferential diffusion physics for flamelet solver.*/
 
   /*--- lookup table ---*/
   unsigned short n_scalars = 0;       /*!< \brief Number of transported scalars for flamelet LUT approach. */
@@ -2138,13 +2143,44 @@ class CConfig {
 
   /*!
    * \brief Get the flame initialization.
-   *        (x1,x2,x3) = flame offset.
-   *        (x4,x5,x6) = flame normal, separating unburnt from burnt.
+   *        (x1,x2,x3) = flame offset/spark center location.
+   *        (x4,x5,x6) = flame normal, separating unburnt from burnt or
+   *                     spark radius, spark start iteration, spark duration.
    *        (x7) = flame thickness, the length from unburnt to burnt conditions.
    *        (x8) = flame burnt thickness, the length to stay at burnt conditions.
-   * \return Flame initialization for the flamelet model.
+   * \return Ignition initialization parameters for the flamelet model.
+   */
+  const su2double* GetFlameInit() const {
+    switch (flame_init_type)
+    {
+    case FLAMELET_INIT_TYPE::FLAME_FRONT:
+      return flame_init;
+      break;
+    case FLAMELET_INIT_TYPE::SPARK:
+      return spark_init;
+      break;
+    default:
+      return nullptr;
+      break;
+    }
+  }
+
+  /*!
+   * \brief Get species net reaction rates applied during spark ignition.
+   */
+  const su2double* GetSpark() const {
+    return spark_reaction_rates;
+  }
+
+  /*!
+   * \brief Preferential diffusion combustion problem.
+   */
+  bool GetPreferentialDiffusion() const { return preferential_diffusion; }
+
+  /*!
+   * \brief Define preferential diffusion combustion problem.
    */
-  const su2double* GetFlameInit() const { return flame_init; }
+  inline void SetPreferentialDiffusion(bool input) { preferential_diffusion = input; }
 
   /*!
    * \brief Get the number of control variables for flamelet model.
@@ -2190,6 +2226,7 @@ class CConfig {
     if (n_user_sources > 0) return user_source_names[i_user_source]; else return none;
   }
 
+  FLAMELET_INIT_TYPE GetFlameletInitType() const { return flame_init_type; }
   /*!
    * \brief Get the number of transported scalars for combustion.
    */

Common/include/containers/CLookUpTable.hpp

@@ -389,7 +389,6 @@ class CLookUpTable {
   /*!
    * \brief Find the table levels with constant z-values directly above and below query val_z.
    * \param[in] val_CV3 - Value of controlling variable 3.
-   * \param[in] within_limits - Whether query point lies within table bounds.
    * \returns Pair of inclusion level indices (first = lower level index, second = upper level index).
    */
   std::pair<unsigned long, unsigned long> FindInclusionLevels(const su2double val_CV3);
@@ -410,6 +409,11 @@ class CLookUpTable {
     return limits_table_x[i_level];
   }
 
+  /*!
+   * \brief Check whether requested set of variables are included in the table.
+   */
+  bool CheckForVariables(const std::vector<std::string>& vars_to_check);
+
   /*!
    * \brief Returns the index to the variable in the lookup table.
    * \param[in] nameVar - Variable name for which to retrieve the column index.

Common/include/option_structure.hpp

@@ -1333,11 +1333,38 @@ enum FLAMELET_SCALAR_SOURCES {
  * \brief Look-up operations for the flamelet scalar solver.
  */
 enum FLAMELET_LOOKUP_OPS {
-  TD,       /*!< \brief Thermochemical properties (temperature, density, diffusivity, etc.). */
+  THERMO,   /*!< \brief Thermochemical properties (temperature, density, diffusivity, etc.). */
+  PREFDIF,  /*!< \brief Preferential diffusion scalars. */
   SOURCES,  /*!< \brief Scalar source terms (controlling variables, passive species).*/
   LOOKUP,   /*!< \brief Passive look-up variables specified in config. */
 };
 
+/*!
+ * \brief the preferential diffusion scalar indices for the preferential diffusion model.
+ */
+enum FLAMELET_PREF_DIFF_SCALARS {
+  I_BETA_PROGVAR,       /*!< \brief Preferential diffusion scalar for the progress variable. */
+  I_BETA_ENTH_THERMAL,  /*!< \brief Preferential diffusion scalar for temperature. */
+  I_BETA_ENTH,          /*!< \brief Preferential diffusion scalar for total enthalpy. */
+  I_BETA_MIXFRAC,       /*!< \brief Preferential diffusion scalar for mixture fraction. */
+  N_BETA_TERMS,         /*!< \brief Total number of preferential diffusion scalars. */
+};
+
+/*!
+ * \brief Flame initialization options for the flamelet solver.
+ */
+enum class FLAMELET_INIT_TYPE {
+  FLAME_FRONT,  /*!< \brief Straight flame front. */
+  SPARK,        /*!< \brief Species reaction rate in a set location. */
+  NONE,         /*!< \brief No ignition, cold flow only. */
+};
+
+static const MapType<std::string, FLAMELET_INIT_TYPE> Flamelet_Init_Map = {
+  MakePair("NONE", FLAMELET_INIT_TYPE::NONE)
+  MakePair("FLAME_FRONT", FLAMELET_INIT_TYPE::FLAME_FRONT)
+  MakePair("SPARK", FLAMELET_INIT_TYPE::SPARK)
+};
+
 /*!
  * \brief Types of subgrid scale models
  */

Common/src/CConfig.cpp

@@ -987,7 +987,7 @@ void CConfig::SetPointersNull() {
   Species_Init           = nullptr;
   Species_Clipping_Min   = nullptr;
   Species_Clipping_Max   = nullptr;
-
+  spark_reaction_rates   = nullptr;
   /*--- Moving mesh pointers ---*/
 
   nKind_SurfaceMovement = 0;
@@ -1376,7 +1376,9 @@ void CConfig::SetConfig_Options() {
   /*!\brief SPECIES_CLIPPING_MIN \n DESCRIPTION: Minimum values for scalar clipping \ingroup Config*/
   addDoubleListOption("SPECIES_CLIPPING_MIN", nSpecies_Clipping_Min, Species_Clipping_Min);
 
-  /*!\brief FLAME_INIT \n DESCRIPTION: flame initialization using the flamelet model \ingroup Config*/
+  /*!\brief FLAME_INIT_METHOD \n DESCRIPTION: Ignition method for flamelet solver \n DEFAULT: no ignition; cold flow only. */
+  addEnumOption("FLAME_INIT_METHOD", flame_init_type, Flamelet_Init_Map, FLAMELET_INIT_TYPE::NONE);
+  /*!\brief FLAME_INIT \n DESCRIPTION: flame front initialization using the flamelet model \ingroup Config*/
   /*--- flame offset (x,y,z) ---*/
   flame_init[0] = 0.0; flame_init[1] = 0.0; flame_init[2] = 0.0;
   /*--- flame normal (nx, ny, nz) ---*/
@@ -1385,6 +1387,13 @@ void CConfig::SetConfig_Options() {
   flame_init[6] = 0.5e-3; flame_init[7] = 1.0;
   addDoubleArrayOption("FLAME_INIT", 8,flame_init);
 
+  /*!\brief SPARK_INIT \n DESCRIPTION: spark initialization using the flamelet model \ingroup Config*/
+  for (auto iSpark=0u; iSpark<6; ++iSpark) spark_init[iSpark]=0;
+  addDoubleArrayOption("SPARK_INIT", 6, spark_init);
+
+  /*!\brief SPARK_REACTION_RATES \n DESCRIPTION: Net source term values applied to species within spark area during spark ignition. \ingroup Config*/
+  addDoubleListOption("SPARK_REACTION_RATES", nspark, spark_reaction_rates);
+
   /*--- Options related to mass diffusivity and thereby the species solver. ---*/
 
   /*!\brief DIFFUSIVITY_MODEL\n DESCRIPTION: mass diffusivity model \n DEFAULT constant disffusivity \ingroup Config*/
@@ -2136,6 +2145,9 @@ void CConfig::SetConfig_Options() {
   /* DESCRIPTION: Names of the user scalar source terms. */
   addStringListOption("USER_SOURCE_NAMES", n_user_sources, user_source_names);
 
+  /* DESCRIPTION: Enable preferential diffusion for FGM simulations. \n DEFAULT: false */
+  addBoolOption("PREFERENTIAL_DIFFUSION", preferential_diffusion, false);
+
   /*!\brief CONV_FILENAME \n DESCRIPTION: Output file convergence history (w/o extension) \n DEFAULT: history \ingroup Config*/
   addStringOption("CONV_FILENAME", Conv_FileName, string("history"));
   /*!\brief BREAKDOWN_FILENAME \n DESCRIPTION: Output file forces breakdown \ingroup Config*/
@@ -9221,7 +9233,7 @@ su2double CConfig::GetIsothermal_Temperature(const string& val_marker) const {
     if (Marker_Isothermal[iMarker_Isothermal] == val_marker)
       return Isothermal_Temperature[iMarker_Isothermal];
 
-  return Isothermal_Temperature[0];
+  return Temperature_FreeStream;
 }
 
 su2double CConfig::GetWall_HeatFlux(const string& val_marker) const {

Common/src/containers/CLookUpTable.cpp

@@ -802,3 +802,15 @@ bool CLookUpTable::IsInTriangle(su2double val_CV1, su2double val_CV2, unsigned l
 
   return (abs(area_tri - (area_0 + area_1 + area_2)) < area_tri * 1e-10);
 }
+
+bool CLookUpTable::CheckForVariables(const std::vector<std::string>& vars_to_check) {
+  bool variables_are_present{true};
+  for (auto iVar = 0u; iVar < vars_to_check.size(); iVar++) {
+    bool var_is_present{false};
+    for (auto jVar = 0u; jVar < names_var.size(); jVar++) {
+      if (vars_to_check[iVar].compare(names_var[jVar]) == 0) var_is_present = true;
+    }
+    if (!var_is_present) variables_are_present = false;
+  }
+  return variables_are_present;
+}

Docs/docmain.hpp

@@ -225,9 +225,3 @@
  * \brief Classes for explicit (done by the programmer) vectorization (SIMD) of computations.
  * \ingroup Toolboxes
  */
-
-/*!
- * \defgroup Multi-Layer Perceptrons (MLP)
- * \brief Data look up and interpolation via dense, feed-forward multi-layer perceptrons.
- * \ingroup Toolboxes
- */

SU2_CFD/include/fluid/CFluidFlamelet.hpp

@@ -34,17 +34,19 @@
 #define USE_MLPCPP
 #endif
 #include "CFluidModel.hpp"
-
+#include <memory>
 class CFluidFlamelet final : public CFluidModel {
  private:
   ENUM_DATADRIVEN_METHOD Kind_DataDriven_Method =
       ENUM_DATADRIVEN_METHOD::LUT; /*!< \brief Interpolation method for data set evaluation. */
 
   enum LOOKUP_TD { TEMPERATURE, HEATCAPACITY, VISCOSITY, CONDUCTIVITY, DIFFUSIONCOEFFICIENT, MOLARWEIGHT, SIZE };
 
+  su2double beta_progvar, beta_enth_thermal, beta_enth, beta_mixfrac;
   int rank;
 
-  bool include_mixture_fraction = false; /*!< \brief include mixture fraction in controlling variables. */
+  bool include_mixture_fraction = false, /*!< \brief include mixture fraction in controlling variables. */
+      PreferentialDiffusion = false;     /*!< \brief use preferential diffusion physics. */
 
   unsigned short n_scalars, n_lookups, n_user_scalars, /*!< \brief number of passive reactant species. */
       n_control_vars;                                  /*!< \brief number of controlling variables. */
@@ -62,12 +64,15 @@ class CFluidFlamelet final : public CFluidModel {
 
   vector<unsigned long> LUT_idx_TD,
                         LUT_idx_Sources,
-                        LUT_idx_LookUp;
+                        LUT_idx_LookUp,
+                        LUT_idx_PD;
 
   /*--- Class variables for the multi-layer perceptron method ---*/
 #ifdef USE_MLPCPP
+  size_t n_betas;
   MLPToolbox::CLookUp_ANN* lookup_mlp; /*!< \brief Multi-layer perceptron collection. */
   MLPToolbox::CIOMap* iomap_TD;        /*!< \brief Input-output map for thermochemical properties. */
+  MLPToolbox::CIOMap* iomap_PD;        /*!< \brief Input-output map for the preferential diffusion scalars. */
   MLPToolbox::CIOMap* iomap_Sources;   /*!< \brief Input-output map for species source terms. */
   MLPToolbox::CIOMap* iomap_LookUp;    /*!< \brief Input-output map for passive look-up terms. */
   MLPToolbox::CIOMap* iomap_Current;
@@ -76,10 +81,14 @@ class CFluidFlamelet final : public CFluidModel {
   vector<su2double> scalars_vector;
 
   vector<string> varnames_TD, /*!< \brief Lookup names for thermodynamic state variables. */
-      varnames_Sources, varnames_LookUp;
+      varnames_Sources,       /*!< \brief Lookup names for source terms. */
+      varnames_LookUp,        /*!< \brief Lookup names for passive look-up terms. */
+      varnames_PD;            /*!< \brief Lookup names for preferential diffusion scalars. */
 
   vector<su2double> val_vars_TD, /*!< \brief References to thermodynamic state variables. */
-      val_vars_Sources, val_vars_LookUp;
+      val_vars_Sources,          /*!< \brief References to source terms. */
+      val_vars_LookUp,           /*!< \brief References passive look-up terms. */
+      val_vars_PD;               /*!< \brief References to preferential diffusion scalars. */
 
   void PreprocessLookUp(CConfig* config);
 
@@ -107,14 +116,14 @@ class CFluidFlamelet final : public CFluidModel {
   void SetTDState_T(su2double val_temperature, const su2double* val_scalars = nullptr) override;
 
   /*!
-   * \brief Evaluate the flamelet manifold.
-   * \param[in] input_scalar - scalar solution.
-   * \param[in] input_varnames - names of variables to evaluate.
-   * \param[in] output_refs - output data.
-   * \param[out] Extrapolation - scalar solution is within bounds (0) or out of bounds (1).
+   * \brief Evaluate data-set for flamelet simulations.
+   * \param[in] input_scalar - controlling variables used to interpolate manifold.
+   * \param[in] lookup_type - look-up operation to be performed (FLAMELET_LOOKUP_OPS)
+   * \param[in] output_refs - output variables where interpolated results are stored.
+   * \param[out] Extrapolation - query data is within manifold bounds (0) or out of bounds (1).
    */
-  inline unsigned long EvaluateDataSet(const vector<su2double>& input_scalar, unsigned short lookup_type,
-                                       vector<su2double>& output_refs) override;
+  unsigned long EvaluateDataSet(const vector<su2double>& input_scalar, unsigned short lookup_type,
+                                       vector<su2double>& output_refs);
 
   /*!
    * \brief Check for out-of-bounds condition for data set interpolation.
@@ -142,4 +151,10 @@ class CFluidFlamelet final : public CFluidModel {
    * \param[out] Mu - value of the laminar viscosity
    */
   inline su2double GetLaminarViscosity() override { return Mu; }
+
+  /*!
+   * \brief Preferential diffusion as relevant phenomenon in flamelet simulations.
+   * \return Inclusion of preferential diffusion model.
+   */
+  inline bool GetPreferentialDiffusion() const override { return PreferentialDiffusion; };
 };