WIP: Generalized actuator disk (#1875)

* First version of generalized actuator disk

* Reading in blade specification table

* Reading in files for generalized actuator disk

* Finalizing generalized actuator disk

* Correcting Windows error

* Correcting SYCL error

* Reading in table for rpm and blade pitch

* Correcting SYCL error

* Correcting unused variable error

* Correcting spelling error

* Correcting docs errors

* Correcting indexing error

---------

Co-authored-by: Mahesh Natarajan <[email protected]>
Co-authored-by: Mahesh Natarajan <[email protected]>
Co-authored-by: Mahesh Natarajan <[email protected]>
Co-authored-by: Mahesh Natarajan <[email protected]>
Co-authored-by: Ann Almgren <[email protected]>
Co-authored-by: Mahesh Natarajan <[email protected]>

Docs/sphinx_doc/theory/WindFarmModels.rst

@@ -127,7 +127,7 @@ The EWP model does not have a concept of intersected area by the turbine rotor l
 .. _actuator_disk_model_simplified:
 
 Simplified actuator disk model
-=================================
+-----------------------------------
 
 A simplified actuator disk model based on one-dimensional momentum theory is implemented (See Section 3.2 in `Wind Energy Handbook 2nd edition`_). A schematic of the actuator disk is shown in Fig. :numref:`fig:ActuatorDisk_Schematic`.
 The model is implemented as source terms in the equations for the horizontal velocity components (ie. `x` and `y` directions). The thrust force from the one-dimensional momentum theory is given by
@@ -185,7 +185,7 @@ where :math:`dA` is the area of the actuator disk in the mesh cell (see Fig. :nu
 .. _generalized_actuator_disk_model:
 
 Generalized actuator disk model
-===============================
+------------------------------------
 
 The generalized actuator model (GAD) based on blade element theory (`Mirocha et. al. 2014`_, see Chapter 3 of `Small Wind Turbines`_) is implemented. Similar to the simplified actuator disk model, GAD also models the wind turbine as a disk, but takes into account the details of the blade geometry (see Fig. :numref:`fig:GAD_Schematic`). The forces on the blades in the x, y, z directions are computed, and that contributes to the source terms for the fluid momentum equations. The source terms in a mesh cell inside the actuator disk are given as:
 

Source/DataStructs/ERF_DataStruct.H

@@ -353,7 +353,8 @@ struct SolverChoice {
  pp.query("windfarm_loc_table", windfarm_loc_table);
  pp.query("windfarm_spec_table", windfarm_spec_table);
  pp.query("windfarm_blade_table", windfarm_blade_table);
- pp.query("windfarm_airofil_tables", windfarm_airfoil_tables);
+ pp.query("windfarm_airfoil_tables", windfarm_airfoil_tables);
+ pp.query("windfarm_spec_table_extra", windfarm_spec_table_extra);
 
  // Sampling distance upstream of the turbine to find the
  // incoming free stream velocity as a factor of the diameter of the
@@ -647,7 +648,7 @@ struct SolverChoice {
  // if SAM, then it will be set to RhoQ4
  int RhoQr_comp {-1};
 
- std::string windfarm_loc_table, windfarm_spec_table;
+ std::string windfarm_loc_table, windfarm_spec_table, windfarm_spec_table_extra;
  std::string windfarm_blade_table, windfarm_airfoil_tables;
  amrex::Real sampling_distance_by_D = -1.0;
  amrex::Real turb_disk_angle = -1.0;

Source/ERF_make_new_arrays.cpp

@@ -239,7 +239,7 @@ ERF::init_stuff (int lev, const BoxArray& ba, const DistributionMapping& dm,
  vars_windfarm[lev].define(ba, dm, 2, ngrow_state);// dudt, dvdt
  }
  if (solverChoice.windfarm_type == WindFarmType::GeneralAD) {
- vars_windfarm[lev].define(ba, dm, 2, ngrow_state);// dudt, dvdt
+ vars_windfarm[lev].define(ba, dm, 3, ngrow_state);// dudt, dvdt, dwdt
  }
  Nturb[lev].define(ba, dm, 1, ngrow_state); // Number of turbines in a cell
  SMark[lev].define(ba, dm, 2, ngrow_state); // Free stream velocity/source term

Source/IO/ERF_Plotfile.cpp

@@ -101,13 +101,9 @@ ERF::setPlotVariables (const std::string& pp_plot_var_names, Vector<std::string>
  tmp_plot_names.push_back(derived_names[i]);
  }
  }
- if(solverChoice.windfarm_type == WindFarmType::SimpleAD) {
- if(derived_names[i] == "num_turb" or derived_names[i] == "SMark0" or derived_names[i] == "Smark1") {
- tmp_plot_names.push_back(derived_names[i]);
- }
- }
- if(solverChoice.windfarm_type == WindFarmType::GeneralAD) {
- if(derived_names[i] == "num_turb" or derived_names[i] == "SMark1") {
+ if( solverChoice.windfarm_type == WindFarmType::SimpleAD or
+ solverChoice.windfarm_type == WindFarmType::GeneralAD ) {
+ if(derived_names[i] == "num_turb" or derived_names[i] == "SMark0" or derived_names[i] == "SMark1") {
  tmp_plot_names.push_back(derived_names[i]);
  }
  }
@@ -486,8 +482,8 @@ ERF::WritePlotFile (int which, Vector<std::string> plot_var_names)
  mf_comp ++;
  }
 
- if(containerHasElement(plot_var_names, "SMark0") and
- solverChoice.windfarm_type == WindFarmType::SimpleAD) {
+ if( containerHasElement(plot_var_names, "SMark0") and
+ (solverChoice.windfarm_type == WindFarmType::SimpleAD or solverChoice.windfarm_type == WindFarmType::GeneralAD) ) {
  for ( MFIter mfi(mf[lev],TilingIfNotGPU()); mfi.isValid(); ++mfi)
  {
  const Box& bx = mfi.tilebox();

Source/Initialization/ERF_init_windfarm.cpp

@@ -43,8 +43,10 @@ ERF::init_windfarm (int lev)
  }
 
  if(solverChoice.windfarm_type == WindFarmType::GeneralAD) {
- //windfarm->read_windfarm_blade_table(solverChoice.windfarm_blade_table);
- //windfarm->read_airfoil_tables
+ windfarm->read_windfarm_blade_table(solverChoice.windfarm_blade_table);
+ windfarm->read_windfarm_airfoil_tables(solverChoice.windfarm_airfoil_tables,
+ solverChoice.windfarm_blade_table);
+ windfarm->read_windfarm_spec_table_extra(solverChoice.windfarm_spec_table_extra);
  }
 }
 

Source/WindFarmParametrization/ERF_InitWindFarm.cpp

@@ -3,6 +3,8 @@
  */
 
 #include <ERF_WindFarm.H>
+#include <filesystem>
+#include <dirent.h> // For POSIX directory handling
 
 using namespace amrex;
 
@@ -123,6 +125,14 @@ WindFarm::init_windfarm_lat_lon (const std::string windfarm_loc_table,
  xloc[it] = xloc[it] - xloc_min + windfarm_x_shift;
  yloc[it] = yloc[it] - yloc_min + windfarm_y_shift;
  }
+
+ FILE* file_xy_loc;
+ file_xy_loc = fopen("file_xy_loc_KingPlains.txt","w");
+
+ for(int it = 0;it<xloc.size(); it++){
+ fprintf(file_xy_loc,"%0.15g %0.15g %0.15g\n", xloc[it], yloc[it], 89.0);
+ }
+ fclose(file_xy_loc);
 }
 
 void
@@ -199,14 +209,152 @@ void
 WindFarm::read_windfarm_blade_table(const std::string windfarm_blade_table)
 {
  std::ifstream filename(windfarm_blade_table);
+ std::string line;
+ Real temp, var1, var2, var3;
  if (!filename.is_open()) {
  Error("You are using a generalized actuator disk model based on blade element theory. This needs info of blades."
  " An entry erf.windfarm_blade_table is needed. Either the entry is missing or the file specified"
  " in the entry - " + windfarm_blade_table + " is missing.");
  }
  else {
  Print() << "Reading in wind farm blade table: " << windfarm_blade_table << "\n";
+
+ // First 6 lines are comments
+
+ for (int i = 0; i < 6; ++i) {
+ if (std::getline(filename, line)) { // Read one line into the array
+ }
+ }
+
+ while(filename >> var1 >> temp >> temp >> temp >> var2 >> var3 >> temp) {
+ bld_rad_loc.push_back(var1);
+ bld_twist.push_back(var2);
+ bld_chord.push_back(var3);
+ //int idx = bld_rad_loc.size()-1;
+ //printf("Values are = %0.15g %0.15g %0.15g\n", bld_rad_loc[idx], bld_twist[idx], bld_chord[idx]);
+ }
+ set_blade_spec(bld_rad_loc, bld_twist, bld_chord);
+ n_bld_sections = bld_rad_loc.size();
+ }
+}
+
+void
+WindFarm::read_windfarm_spec_table_extra(const std::string windfarm_spec_table_extra)
+{
+ // Open the file
+ std::ifstream file(windfarm_spec_table_extra);
+
+ // Check if file opened successfully
+ if (!file.is_open()) {
+ Abort("Error: You are using generalized wind farms option. This requires an input file erf.windfarm_spec_table_extra."
+ " Either this entry is missing in the inputs or the file specified -" + windfarm_spec_table_extra + " does"
+ " not exist. Exiting...");
+ } else {
+ printf("Reading in windfarm_spec_table_extra %s", windfarm_spec_table_extra.c_str());
+ }
+
+ // Ignore the first line (header)
+ std::string header;
+ std::getline(file, header);
+
+ // Variables to hold each row's values
+ double V, Cp, Ct, rpm, pitch, temp;
+
+ // Read the file row by row
+ while (file >> V) {
+ char comma; // To ignore the commas
+ file >> comma >> Cp >> comma >> Ct >> comma >> temp >> comma >> temp >> comma
+ >> temp >> comma >> rpm >> comma >> pitch >> comma >> temp;
+
+ velocity.push_back(V);
+ C_P.push_back(Cp);
+ C_T.push_back(Ct);
+ rotor_RPM.push_back(rpm);
+ blade_pitch.push_back(pitch);
+ }
+
+ set_turb_spec_extra(velocity, C_P, C_T, rotor_RPM, blade_pitch);
+}
+
+
+void
+WindFarm::read_windfarm_airfoil_tables(const std::string windfarm_airfoil_tables,
+ const std::string windfarm_blade_table)
+{
+ DIR* dir;
+ struct dirent* entry;
+ std::vector<std::string> files;
+
+ // Check if directory exists
+ if ((dir = opendir(windfarm_airfoil_tables.c_str())) == nullptr) {
+ Abort("You are using a generalized actuator disk model based on blade element theory. This needs info of airfoil"
+ " cross sections over the span of the blade. There needs to be an entry erf.airfoil_tables which is the directory that"
+ " contains the angle of attack, Cl, Cd data for each airfoil cross-section. Either the entry is missing or the directory specified"
+ " in the entry - " + windfarm_airfoil_tables + " is missing. Exiting...");
+ }
+
+ // Loop through directory entries and collect filenames
+ while ((entry = readdir(dir)) != nullptr) {
+ // Skip special directory entries "." and ".."
+ if (std::string(entry->d_name) == "." || std::string(entry->d_name) == "..") {
+ continue;
+ }
+ files.emplace_back(windfarm_airfoil_tables + "/" + entry->d_name); // Add file path to vector
  }
+
+ // Close the directory
+ closedir(dir);
+
+ if (files.empty()) {
+ Abort("It seems the directory containing the info of airfoil cross sections of the blades - " + windfarm_airfoil_tables +
+ " is empty. Exiting...");
+ }
+
+ if(files.size() != static_cast<long double>(n_bld_sections)) {
+ printf("There are %d airfoil sections in the last column of %s. But the number"
+ " of files in %s is only %ld.\n", n_bld_sections, windfarm_blade_table.c_str(),
+ windfarm_airfoil_tables.c_str(), files.size());
+ Abort("The number of blade sections from " + windfarm_blade_table + " should match the number of"
+ " files in " + windfarm_airfoil_tables + ". Exiting...");
+ }
+
+ // Sort filenames in lexicographical (alphabetical) order
+ std::sort(files.begin(), files.end());
+
+ // Process each file
+ int count = 0;
+ bld_airfoil_aoa.resize(n_bld_sections);
+ bld_airfoil_Cl.resize(n_bld_sections);
+ bld_airfoil_Cd.resize(n_bld_sections);
+ for (const auto& filePath : files) {
+ std::ifstream filename(filePath.c_str());
+
+ if (!filename.is_open()) {
+ std::cerr << "Failed to open file: " << filePath << std::endl;
+ continue; // Move on to the next file
+ }
+
+ std::cout << "Reading file: " << filePath << std::endl;
+
+ std::string line;
+ for (int i = 0; i < 54; ++i) {
+ if (std::getline(filename, line)) { // Read one line into the array
+ }
+ }
+
+ Real var1, var2, var3, temp;
+
+ while(filename >> var1 >> var2 >> var3 >> temp) {
+ bld_airfoil_aoa[count].push_back(var1);
+ bld_airfoil_Cl[count].push_back(var2);
+ bld_airfoil_Cd[count].push_back(var3);
+ //int idx = bld_airfoil_aoa.size()-1;
+ //printf("Values are = %0.15g %0.15g %0.15g\n", bld_airfoil_aoa[idx], bld_airfoil_Cl[idx], bld_airfoil_Cd[idx]);
+ }
+ count++;
+ }
+
+ set_blade_airfoil_spec(bld_airfoil_aoa, bld_airfoil_Cl, bld_airfoil_Cd);
 }
 
 void

Source/WindFarmParametrization/ERF_WindFarm.H

@@ -65,7 +65,10 @@ public:
 
  void read_windfarm_blade_table(const std::string windfarm_blade_table);
 
- void read_windfarm_airofil_tables(const std::string windfarm_airfoils_tables);
+ void read_windfarm_airfoil_tables(const std::string windfarm_airfoil_tables,
+ const std::string windfarm_blade_table);
+
+ void read_windfarm_spec_table_extra(const std::string windfarm_spec_table_extra);
 
  void fill_Nturb_multifab(const amrex::Geometry& geom,
  amrex::MultiFab& mf_Nturb);
@@ -108,9 +111,32 @@ public:
  m_windfarm_model[0]->set_turb_loc(a_xloc, a_yloc);
  }
 
- void set_turb_disk_angle (const amrex::Real& turb_disk_angle) override
+ void set_turb_disk_angle (const amrex::Real& a_turb_disk_angle) override
+ {
+ m_windfarm_model[0]->set_turb_disk_angle(a_turb_disk_angle);
+ }
+
+ void set_blade_spec (const amrex::Vector<amrex::Real>& a_bld_rad_loc,
+ const amrex::Vector<amrex::Real>& a_bld_twist,
+ const amrex::Vector<amrex::Real>& a_bld_chord) override
+ {
+ m_windfarm_model[0]->set_blade_spec(a_bld_rad_loc, a_bld_twist, a_bld_chord);
+ }
+
+ void set_blade_airfoil_spec (const amrex::Vector<amrex::Vector<amrex::Real>>& a_bld_airfoil_aoa,
+ const amrex::Vector<amrex::Vector<amrex::Real>>& a_bld_airfoil_Cl,
+ const amrex::Vector<amrex::Vector<amrex::Real>>& a_bld_airfoil_Cd) override
+ {
+ m_windfarm_model[0]->set_blade_airfoil_spec(a_bld_airfoil_aoa, a_bld_airfoil_Cl, a_bld_airfoil_Cd);
+ }
+
+ void set_turb_spec_extra (const amrex::Vector<amrex::Real>& a_velocity,
+ const amrex::Vector<amrex::Real>& a_C_P,
+ const amrex::Vector<amrex::Real>& a_C_T,
+ const amrex::Vector<amrex::Real>& a_rotor_RPM,
+ const amrex::Vector<amrex::Real>& a_blade_pitch) override
  {
- m_windfarm_model[0]->set_turb_disk_angle(turb_disk_angle);
+ m_windfarm_model[0]->set_turb_spec_extra(a_velocity, a_C_P, a_C_T, a_rotor_RPM, a_blade_pitch);
  }
 
 protected:
@@ -119,6 +145,10 @@ protected:
  amrex::Real my_turb_disk_angle;
  amrex::Real hub_height, rotor_rad, thrust_coeff_standing, nominal_power;
  amrex::Vector<amrex::Real> wind_speed, thrust_coeff, power;
+ amrex::Vector<amrex::Real> bld_rad_loc, bld_twist, bld_chord;
+ amrex::Vector<amrex::Vector<amrex::Real>> bld_airfoil_aoa, bld_airfoil_Cl, bld_airfoil_Cd;
+ int n_bld_sections;
+ amrex::Vector<amrex::Real> velocity, C_P, C_T, rotor_RPM, blade_pitch;
 
  /*! \brief Create and set the specified windfarm model */
  template<class NewWindFarmModel>