Merge branch 'HeatTransportBHE_MassLumping' into 'master'

Enable Mass Lumping in Heat Transport BHE

See merge request ogs/ogs!5121

Documentation/ProjectFile/prj/processes/process/HEAT_TRANSPORT_BHE/t_mass_lumping.md

+The default setting is false.
+If set, mass lumping is applied to the BHE connected soil elements.
+With mass lumping, the non-physical oscillation of temperatures in the direct vicinity of the BHE can be improved.

ProcessLib/HeatTransportBHE/CreateHeatTransportBHEProcess.cpp

@@ -176,6 +176,10 @@ std::unique_ptr<Process> createHeatTransportBHEProcess(
         //! \ogs_file_param{prj__processes__process__HEAT_TRANSPORT_BHE__use_server_communication}
         config.getConfigParameter<bool>("use_server_communication", false);
 
+    auto const mass_lumping =
+        //! \ogs_file_param{prj__processes__process__HEAT_TRANSPORT_BHE__mass_lumping}
+        config.getConfigParameter<bool>("mass_lumping", false);
+
     auto const using_algebraic_bc =
         //! \ogs_file_param{prj__processes__process__HEAT_TRANSPORT_BHE__use_algebraic_bc}
         config.getConfigParameter<bool>("use_algebraic_bc", false);
@@ -331,7 +335,7 @@ std::unique_ptr<Process> createHeatTransportBHEProcess(
 
     HeatTransportBHEProcessData process_data(
         std::move(media_map), std::move(bhes), py_object, using_tespy,
-        using_server_communication,
+        using_server_communication, mass_lumping,
         {using_algebraic_bc, weighting_factor, is_linear});
 
     SecondaryVariableCollection secondary_variables;

ProcessLib/HeatTransportBHE/HeatTransportBHEProcess.cpp

@@ -14,6 +14,7 @@
 
 #include "BoundaryConditions/BHEBottomDirichletBoundaryCondition.h"
 #include "BoundaryConditions/BHEInflowDirichletBoundaryCondition.h"
+#include "MeshLib/MeshSearch/ElementSearch.h"
 #include "ProcessLib/BoundaryConditionAndSourceTerm/Python/BHEInflowPythonBoundaryCondition.h"
 #include "ProcessLib/HeatTransportBHE/BHE/MeshUtils.h"
 #include "ProcessLib/HeatTransportBHE/LocalAssemblers/CreateLocalAssemblers.h"
@@ -157,6 +158,27 @@ void HeatTransportBHEProcess::initializeConcreteProcess(
 
     // Create BHE boundary conditions for each of the BHEs
     createBHEBoundaryConditionTopBottom(_bheMeshData.BHE_nodes);
+
+    if (_process_data._mass_lumping)
+    {
+        std::vector<std::size_t> const bhes_node_ids =
+            _bheMeshData.BHE_nodes | ranges::views::join |
+            ranges::views::transform([](auto const* const node)
+                                     { return node->getID(); }) |
+            ranges::to<std::vector>;
+
+        // all connected soil elements and also the BHE elements.
+        MeshLib::ElementSearch es{mesh};
+        es.searchByNodeIDs(bhes_node_ids);
+
+        assert(_process_data.mass_lumping_soil_elements.empty());
+        _process_data.mass_lumping_soil_elements.resize(
+            mesh.getNumberOfElements(), false);
+        for (auto const id : es.getSearchedElementIDs())
+        {
+            _process_data.mass_lumping_soil_elements[id] = true;
+        }
+    }
 }
 
 void HeatTransportBHEProcess::assembleConcreteProcess(

ProcessLib/HeatTransportBHE/HeatTransportBHEProcessData.h

@@ -41,12 +41,14 @@ struct HeatTransportBHEProcessData final
             nullptr,
         const bool use_tespy = false,
         const bool use_server_communication = false,
+        const bool mass_lumping = false,
         AlgebraicBCSetting algebraicBCSetting = {false, 100.0, false})
         : media_map(media_map_),
           _vec_BHE_property(std::move(vec_BHEs_)),
           py_bc_object(py_bc_object_),
           _use_tespy(use_tespy),
           _use_server_communication(use_server_communication),
+          _mass_lumping(mass_lumping),
           _algebraic_BC_Setting(algebraicBCSetting)
     {
     }
@@ -64,6 +66,10 @@ struct HeatTransportBHEProcessData final
 
     const bool _use_server_communication;
 
+    const bool _mass_lumping;
+
+    std::vector<bool> mass_lumping_soil_elements;
+
     AlgebraicBCSetting const _algebraic_BC_Setting;
 };
 }  // namespace ProcessLib::HeatTransportBHE

ProcessLib/HeatTransportBHE/LocalAssemblers/HeatTransportBHELocalAssemblerSoil-impl.h

@@ -19,6 +19,7 @@
 #include "NumLib/Fem/InitShapeMatrices.h"
 #include "NumLib/Fem/Interpolation.h"
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
+#include "ProcessLib/HeatTransportBHE/HeatTransportBHEProcess.h"
 #include "ProcessLib/HeatTransportBHE/HeatTransportBHEProcessData.h"
 #include "SecondaryData.h"
 
@@ -184,11 +185,20 @@ void HeatTransportBHELocalAssemblerSoil<ShapeFunction>::assemble(
                               density_f * heat_capacity_f * porosity);
     }
 
-    // debugging
-    // std::string sep = "\n----------------------------------------\n";
-    // Eigen::IOFormat CleanFmt(4, 0, ", ", "\n", "[", "]");
-    // std::cout << local_K.format(CleanFmt) << sep;
-    // std::cout << local_M.format(CleanFmt) << sep;
+    if (_process_data._mass_lumping)
+    {
+        // only mass lumping at the BHE connected soil elements
+        if (_process_data.mass_lumping_soil_elements[_element_id])
+        {
+            local_M = local_M.colwise().sum().eval().asDiagonal();
+        }
+    }
+
+    //  debugging
+    //  std::string sep = "\n----------------------------------------\n";
+    //  Eigen::IOFormat CleanFmt(4, 0, ", ", "\n", "[", "]");
+    //  std::cout << local_K.format(CleanFmt) << sep;
+    //  std::cout << local_M.format(CleanFmt) << sep;
 }
 
 template <typename ShapeFunction>

ProcessLib/HeatTransportBHE/Tests.cmake

@@ -124,6 +124,20 @@ AddTest(
     beier_sandbox_ts_10_t_600.000000.vtu beier_sandbox_algebraic_bc_ts_10_t_600.000000.vtu temperature_soil temperature_soil 0 5e-10
 )
 
+AddTest(
+    NAME HeatTransportBHE_1U_3D_MassLumping
+    PATH Parabolic/T/3D_Beier_sandbox
+    EXECUTABLE ogs
+    EXECUTABLE_ARGS beier_sandbox_MassLumping.xml
+    WRAPPER time
+    TESTER vtkdiff
+    REQUIREMENTS NOT OGS_USE_MPI
+    RUNTIME 20
+    DIFF_DATA
+    beier_sandbox_ts_10_t_600.000000.vtu beier_sandbox_mass_lumping_ts_10_t_600.000000.vtu temperature_BHE1 temperature_BHE1 0 1e-6
+    beier_sandbox_ts_10_t_600.000000.vtu beier_sandbox_mass_lumping_ts_10_t_600.000000.vtu temperature_soil temperature_soil 0 1e-4
+)
+
 AddTest(
     NAME HeatTransportBHE_1U_beier_sandbox_fixed_power_constant_flow
     PATH Parabolic/T/3D_Beier_sandbox

Tests/Data/Parabolic/T/3D_Beier_sandbox/beier_sandbox_MassLumping.xml

+<?xml version="1.0" encoding="ISO-8859-1"?>
+<OpenGeoSysProjectDiff base_file="beier_sandbox.prj">
+    <add sel="/*/processes/process">
+        <mass_lumping>true</mass_lumping>
+    </add>
+    <replace sel="/*/time_loop/output/prefix/text()">beier_sandbox_mass_lumping</replace>
+</OpenGeoSysProjectDiff>