Merge pull request #4739 from nilsdeppe/send_cell_centered_fluxes

Send cell centered fluxes
sxs-collaboration · Feb 27, 2023 · cdd15ca · cdd15ca
2 parents 57e51ad + df8904e
commit cdd15ca
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Showing 3 changed files with 32 additions and 9 deletions.
diff --git a/src/Evolution/DgSubcell/PrepareNeighborData.hpp b/src/Evolution/DgSubcell/PrepareNeighborData.hpp
@@ -8,6 +8,8 @@
 #include <utility>
 
 #include "DataStructures/DataBox/DataBox.hpp"
+#include "DataStructures/DataBox/PrefixHelpers.hpp"
+#include "DataStructures/DataBox/Prefixes.hpp"
 #include "DataStructures/DataVector.hpp"
 #include "DataStructures/Index.hpp"
 #include "Domain/Structure/Direction.hpp"
@@ -53,8 +55,12 @@ namespace evolution::dg::subcell {
  * elide any slicing or projection cost in that direction.
  */
 template <typename Metavariables, typename DbTagsList, size_t Dim>
-auto prepare_neighbor_data(const gsl::not_null<Mesh<Dim>*> ghost_data_mesh,
-                           const gsl::not_null<db::DataBox<DbTagsList>*> box)
+auto prepare_neighbor_data(
+    const gsl::not_null<Mesh<Dim>*> ghost_data_mesh,
+    const gsl::not_null<db::DataBox<DbTagsList>*> box,
+    [[maybe_unused]] const Variables<db::wrap_tags_in<
+        ::Tags::Flux, typename Metavariables::system::flux_variables,
+        tmpl::size_t<Dim>, Frame::Inertial>>& volume_fluxes)
     -> DirectionMap<Metavariables::volume_dim, DataVector> {
   const Mesh<Dim>& dg_mesh = db::get<::domain::Tags::Mesh<Dim>>(*box);
   const Mesh<Dim>& subcell_mesh =

diff --git a/src/Evolution/DiscontinuousGalerkin/Actions/ComputeTimeDerivative.hpp b/src/Evolution/DiscontinuousGalerkin/Actions/ComputeTimeDerivative.hpp
@@ -58,8 +58,12 @@ namespace evolution::dg::subcell {
 // We use a forward declaration instead of including a header file to avoid
 // coupling to the DG-subcell libraries for executables that don't use subcell.
 template <typename Metavariables, typename DbTagsList, size_t Dim>
-auto prepare_neighbor_data(gsl::not_null<Mesh<Dim>*> ghost_data_mesh,
-                           gsl::not_null<db::DataBox<DbTagsList>*> box)
+auto prepare_neighbor_data(
+    gsl::not_null<Mesh<Dim>*> ghost_data_mesh,
+    gsl::not_null<db::DataBox<DbTagsList>*> box,
+    [[maybe_unused]] const Variables<db::wrap_tags_in<
+        ::Tags::Flux, typename Metavariables::system::flux_variables,
+        tmpl::size_t<Dim>, Frame::Inertial>>& volume_fluxes)
     -> DirectionMap<Metavariables::volume_dim, DataVector>;
 template <typename DbTagsList>
 int get_tci_decision(const db::DataBox<DbTagsList>& box);
@@ -353,7 +357,10 @@ struct ComputeTimeDerivative {
             typename Metavariables>
   static void send_data_for_fluxes(
       gsl::not_null<Parallel::GlobalCache<Metavariables>*> cache,
-      gsl::not_null<db::DataBox<DbTagsList>*> box);
+      gsl::not_null<db::DataBox<DbTagsList>*> box,
+      [[maybe_unused]] const Variables<db::wrap_tags_in<
+          ::Tags::Flux, typename EvolutionSystem::flux_variables,
+          tmpl::size_t<Dim>, Frame::Inertial>>& volume_fluxes);
 };
 
 template <size_t Dim, typename EvolutionSystem, typename DgStepChoosers,
@@ -606,7 +613,7 @@ ComputeTimeDerivative<Dim, EvolutionSystem, DgStepChoosers, LocalTimeStepping>::
   }
 
   send_data_for_fluxes<ParallelComponent>(make_not_null(&cache),
-                                          make_not_null(&box));
+                                          make_not_null(&box), volume_fluxes);
   return {Parallel::AlgorithmExecution::Continue, std::nullopt};
 }
 
@@ -618,7 +625,10 @@ void ComputeTimeDerivative<Dim, EvolutionSystem, DgStepChoosers,
                            LocalTimeStepping>::
     send_data_for_fluxes(
         const gsl::not_null<Parallel::GlobalCache<Metavariables>*> cache,
-        const gsl::not_null<db::DataBox<DbTagsList>*> box) {
+        const gsl::not_null<db::DataBox<DbTagsList>*> box,
+        [[maybe_unused]] const Variables<db::wrap_tags_in<
+            ::Tags::Flux, typename EvolutionSystem::flux_variables,
+            tmpl::size_t<Dim>, Frame::Inertial>>& volume_fluxes) {
   auto& receiver_proxy =
       Parallel::get_parallel_component<ParallelComponent>(*cache);
   const auto& element = db::get<domain::Tags::Element<Dim>>(*box);
@@ -637,7 +647,7 @@ void ComputeTimeDerivative<Dim, EvolutionSystem, DgStepChoosers,
   if constexpr (using_subcell_v<Metavariables>) {
     all_neighbor_data_for_reconstruction =
         evolution::dg::subcell::prepare_neighbor_data<Metavariables>(
-            make_not_null(&ghost_data_mesh), box);
+            make_not_null(&ghost_data_mesh), box, volume_fluxes);
     tci_decision = evolution::dg::subcell::get_tci_decision(*box);
   }
 

diff --git a/tests/Unit/Evolution/DgSubcell/Test_PrepareNeighborData.cpp b/tests/Unit/Evolution/DgSubcell/Test_PrepareNeighborData.cpp
@@ -47,6 +47,7 @@ struct Metavariables {
 
   struct system {
     using variables_tag = ::Tags::Variables<tmpl::list<Var1>>;
+    using flux_variables = tmpl::list<Var1>;
   };
 
   struct SubcellOptions {
@@ -149,6 +150,12 @@ void test(const bool all_neighbors_are_doing_dg) {
 
   Variables<tmpl::list<Var1>> vars{dg_mesh.number_of_grid_points(), 0.0};
   get(get<Var1>(vars)) = get<0>(logical_coordinates(dg_mesh));
+  using flux_tag = ::Tags::Flux<Var1, tmpl::size_t<Dim>, Frame::Inertial>;
+  Variables<tmpl::list<flux_tag>> volume_fluxes{dg_mesh.number_of_grid_points(),
+                                                0.0};
+  for (size_t i = 0; i < Dim; ++i) {
+    get<flux_tag>(volume_fluxes).get(i) = logical_coordinates(dg_mesh).get(i);
+  }
 
   const size_t ghost_zone_size = 2;
   auto box = db::create<tmpl::list<GhostZoneSize, domain::Tags::Mesh<Dim>,
@@ -162,7 +169,7 @@ void test(const bool all_neighbors_are_doing_dg) {
   Mesh<Dim> ghost_data_mesh{};
   const auto data_for_neighbors =
       evolution::dg::subcell::prepare_neighbor_data<Metavariables<Dim>>(
-          make_not_null(&ghost_data_mesh), make_not_null(&box));
+          make_not_null(&ghost_data_mesh), make_not_null(&box), volume_fluxes);
 
   CHECK(ghost_data_mesh ==
         (all_neighbors_are_doing_dg ? dg_mesh : subcell_mesh));