Merge pull request #28021 from GiudGiud/PR_loge

Facilitate use of TFPs with (v,e) variable set

modules/fluid_properties/doc/content/source/fluidproperties/TabulatedFluidProperties.md

@@ -90,8 +90,8 @@ With a (specific volume, specific energy) variable set, the syntax shown in the
 
 ### Writing data file
 
-If no tabulated fluid property data file exists, then data for the properties specified in the
-input file parameter *interpolated_properties* will be generated using the pressure and temperature
+The `TabulatedFluidProperties`-derived classes can write a file containing the data for the properties specified in the
+input file parameter *interpolated_properties*. It will use the pressure and temperature
 ranges specified in the input file at the beginning of the simulation.
 
 For example, if we wish to generate a file containing tabulated properties for CO$_2$ density, enthalpy
@@ -106,7 +106,7 @@ divided into 50 and 100 equal points, respectively, then the input file syntax n
   [tabulated]
     type = TabulatedBicubicFluidProperties
     fp = co2
-    fluid_property_file = fluid_properties.csv
+    fluid_property_output_file = fluid_properties.csv
     interpolated_properties = 'density enthalpy viscosity'
 
     # Bounds of interpolation
@@ -131,6 +131,11 @@ times the property members in the FluidProperties object are used, the initial t
 the data and the subsequent interpolation time can be much less than using the original
 FluidProperties object.
 
+Using the  [!param](/FluidProperties/TabulatedFluidProperties/construct_pT_from_ve) parameter and the
+[!param](/FluidProperties/TabulatedFluidProperties/fluid_property_output_file) parameters, a tabulation
+using the (specific volume, specific internal energy) variables can be generated. The output file name
+for this additional tabulation will be suffixed with `_ve.csv`.
+
 !alert note
 All fluid properties read from a file or specified in the input file (and their derivatives with
 respect to pressure and temperature) will be calculated through interpolation, while all
@@ -179,6 +184,7 @@ alternative variable sets. This is done in several sets, described for the $(v,e
   the specified bounds on pressure and temperature : $e_{min/max} = e(p_{min/max}, T_{min/max})$, else the bounds
   are chosen from the tabulated data. The number of points in the grid in both dimensions are user-selected parameters.
   The v grid may be created using base-10 log-spacing by setting [!param](/FluidProperties/TabulatedFluidProperties/use_log_grid_v).
+  The e grid may be created using base-10 log-spacing by setting [!param](/FluidProperties/TabulatedFluidProperties/use_log_grid_e).
 
 - These bounds may not be physically realizable simultaneously. It could be that the fluid may not have both $v=v_{min}$
   and $e=e_{min}$. Part of the grid may not be physical.

modules/fluid_properties/include/fluidproperties/TabulatedFluidProperties.h

@@ -170,8 +170,10 @@ class TabulatedFluidProperties : public SinglePhaseFluidProperties
    */
   virtual void generateTabulatedData();
 
-  /// File name of tabulated data file
-  FileName _file_name;
+  /// File name of input tabulated data file
+  FileName _file_name_in;
+  /// File name of output tabulated data file
+  FileName _file_name_out;
   /// Pressure vector
   std::vector<Real> _pressure;
   /// Temperature vector
@@ -199,6 +201,8 @@ class TabulatedFluidProperties : public SinglePhaseFluidProperties
 
   /// SinglePhaseFluidPropertiesPT UserObject
   const SinglePhaseFluidProperties * const _fp;
+  /// Whether to allow a fp object when a tabulation is in use
+  const bool _allow_fp_and_tabulation;
 
   /// List of required column names to be read
   const std::vector<std::string> _required_columns{"pressure", "temperature"};
@@ -246,8 +250,10 @@ class TabulatedFluidProperties : public SinglePhaseFluidProperties
   unsigned int _num_e;
   /// to error or not on out-of-bounds check
   bool _error_on_out_of_bounds;
-  /// log-space the specific volume instead of linear
+  /// log-space the specific volume interpolation grid axis instead of linear
   bool _log_space_v;
+  /// log-space the internal energy interpolation grid axis instead of linear
+  bool _log_space_e;
 
   /// Bi-dimensional interpolation of temperature from (v,e)
   std::unique_ptr<BidimensionalInterpolation> _T_from_v_e_ipol;

modules/fluid_properties/src/fluidproperties/TabulatedBicubicFluidProperties.C

@@ -117,12 +117,28 @@ TabulatedBicubicFluidProperties::constructInterpolation()
       _e_min = *min_element(_properties[_internal_energy_idx].begin(),
                             _properties[_internal_energy_idx].end());
     }
-    Real de = (_e_max - _e_min) / ((Real)_num_e - 1);
 
     // Create e grid for interpolation
     _internal_energy.resize(_num_e);
-    for (unsigned int j = 0; j < _num_e; ++j)
-      _internal_energy[j] = _e_min + j * de;
+    if (_log_space_e)
+    {
+      // incrementing the exponent linearly will yield a log-spaced grid after taking the value to
+      // the power of 10
+      if (_e_min < 0)
+        mooseError("Logarithmic grid in specific energy can only be used with a positive specific "
+                   "energy. Current minimum: " +
+                   std::to_string(_e_min));
+      Real de = (std::log10(_e_max) - std::log10(_e_min)) / ((Real)_num_e - 1);
+      Real log_e_min = std::log10(_e_min);
+      for (const auto j : make_range(_num_e))
+        _internal_energy[j] = std::pow(10, log_e_min + j * de);
+    }
+    else
+    {
+      Real de = (_e_max - _e_min) / ((Real)_num_e - 1);
+      for (const auto j : make_range(_num_e))
+        _internal_energy[j] = _e_min + j * de;
+    }
 
     // initialize vectors for interpolation
     std::vector<std::vector<Real>> p_from_v_e(_num_v);
@@ -404,13 +420,15 @@ TabulatedBicubicFluidProperties::outputWarnings(unsigned int num_nans_p,
   std::string T_nans = "- " + std::to_string(num_nans_T) + " nans generated out of " +
                        std::to_string(number_points) + " points for temperature\n";
   std::string p_oob = "- " + std::to_string(num_out_bounds_p) + " of " +
-                      std::to_string(number_points) +
-                      " pressure values were out of user defined bounds\n";
+                      std::to_string(number_points) + " pressure values were out of bounds\n";
   std::string T_oob = "- " + std::to_string(num_out_bounds_T) + " of " +
-                      std::to_string(number_points) +
-                      " temperature values were out of user defined bounds\n";
+                      std::to_string(number_points) + " temperature values were out of bounds\n";
   std::string outcome = "The pressure and temperature values were replaced with their respective "
-                        "user-defined min and max values.\n";
+                        "min and max values.\n";
+
+  // bounds are different depending on how the object is used
+  std::string source = (_fp ? "from input parameters" : "from tabulation file");
+
   // if any of these do not exist, do not want to print them
   if (convergence_failures)
     warning_message += converge_fails;
@@ -419,9 +437,17 @@ TabulatedBicubicFluidProperties::outputWarnings(unsigned int num_nans_p,
   if (num_nans_T)
     warning_message += T_nans;
   if (num_out_bounds_p)
+  {
     warning_message += p_oob;
+    warning_message += ("Pressure bounds " + source + ": [" + std::to_string(_pressure_min) + ", " +
+                        std::to_string(_pressure_max) + "]\n");
+  }
   if (num_out_bounds_T)
+  {
     warning_message += T_oob;
+    warning_message += ("Temperature bounds " + source + ": [" + std::to_string(_temperature_min) +
+                        ", " + std::to_string(_temperature_max) + "]\n");
+  }
   // print warning
   if (num_nans_p || num_nans_T || num_out_bounds_p || num_out_bounds_T || convergence_failures)
     mooseWarning(warning_message + outcome);