Line data Source code
1 0 : // Distributed under the MIT License. 2 : // See LICENSE.txt for details. 3 : 4 : #pragma once 5 : 6 : #include <cstddef> 7 : #include <optional> 8 : #include <ostream> 9 : 10 : #include "DataStructures/DataBox/Prefixes.hpp" 11 : #include "DataStructures/DataVector.hpp" 12 : #include "DataStructures/Tensor/TypeAliases.hpp" 13 : #include "DataStructures/Variables.hpp" 14 : #include "NumericalAlgorithms/DiscontinuousGalerkin/Formulation.hpp" 15 : #include "NumericalAlgorithms/LinearOperators/Divergence.hpp" 16 : #include "NumericalAlgorithms/LinearOperators/PartialDerivatives.hpp" 17 : #include "NumericalAlgorithms/Spectral/Mesh.hpp" 18 : #include "Utilities/Gsl.hpp" 19 : #include "Utilities/TMPL.hpp" 20 : 21 : namespace evolution::dg::Actions::detail { 22 : /* 23 : * Computes the volume terms for a discontinuous Galerkin scheme. 24 : * 25 : * The function does the following (in order): 26 : * 27 : * 1. Compute the partial derivatives of the `System::gradient_variables`. 28 : * 29 : * The partial derivatives are needed in the nonconservative product terms 30 : * of the evolution equations. Any variable whose evolution equation does 31 : * not contain a flux must contain a nonconservative product and the 32 : * variable must be listed in the `System::gradient_variables` type alias. 33 : * The partial derivatives are also needed for adding the moving mesh terms 34 : * to the equations that do not have a flux term. 35 : * 36 : * 2. The volume time derivatives are calculated from 37 : * `System::compute_volume_time_derivative_terms` 38 : * 39 : * The source terms and nonconservative products are contributed directly 40 : * to the `dt_vars` arguments passed to the time derivative function, while 41 : * the volume fluxes are computed into the `volume_fluxes` arguments. The 42 : * divergence of the volume fluxes will be computed and added to the time 43 : * derivatives later in the function. 44 : * 45 : * 3. If the mesh is moving the appropriate mesh velocity terms are added to 46 : * the equations. 47 : * 48 : * For equations with fluxes this means that \f$-v^i_g u_\alpha\f$ is 49 : * added to the fluxes and \f$-u_\alpha \partial_i v^i_g\f$ is added 50 : * to the time derivatives. For equations without fluxes 51 : * \f$v^i\partial_i u_\alpha\f$ is added to the time derivatives. 52 : * 53 : * 4. Compute flux divergence contribution and add it to the time derivatives. 54 : * 55 : * Either the weak or strong form can be used. Currently only the strong 56 : * form is coded, but adding the weak form is quite easy. 57 : * 58 : * Note that the computation of the flux divergence and adding that to the 59 : * time derivative must be done *after* the mesh velocity is subtracted 60 : * from the fluxes. 61 : */ 62 : template <typename ComputeVolumeTimeDerivativeTerms, size_t Dim, 63 : typename... TimeDerivativeArguments, typename... VariablesTags, 64 : typename... PartialDerivTags, typename... FluxVariablesTags, 65 : typename... TemporaryTags> 66 : void volume_terms( 67 : const gsl::not_null<Variables<tmpl::list<::Tags::dt<VariablesTags>...>>*> 68 : dt_vars_ptr, 69 : [[maybe_unused]] const gsl::not_null<Variables<tmpl::list<::Tags::Flux< 70 : FluxVariablesTags, tmpl::size_t<Dim>, Frame::Inertial>...>>*> 71 : volume_fluxes, 72 : [[maybe_unused]] const gsl::not_null<Variables<tmpl::list<::Tags::deriv< 73 : PartialDerivTags, tmpl::size_t<Dim>, Frame::Inertial>...>>*> 74 : partial_derivs, 75 : [[maybe_unused]] const gsl::not_null< 76 : Variables<tmpl::list<TemporaryTags...>>*> 77 : temporaries, 78 : [[maybe_unused]] const gsl::not_null< 79 : Variables<tmpl::list<::Tags::div<::Tags::Flux< 80 : FluxVariablesTags, tmpl::size_t<Dim>, Frame::Inertial>>...>>*> 81 : div_fluxes, 82 : const Variables<tmpl::list<VariablesTags...>>& evolved_vars, 83 : const ::dg::Formulation dg_formulation, const Mesh<Dim>& mesh, 84 : [[maybe_unused]] const tnsr::I<DataVector, Dim, Frame::Inertial>& 85 : inertial_coordinates, 86 : const InverseJacobian<DataVector, Dim, Frame::ElementLogical, 87 : Frame::Inertial>& 88 : logical_to_inertial_inverse_jacobian, 89 : [[maybe_unused]] const Scalar<DataVector>* const det_inverse_jacobian, 90 : const std::optional<tnsr::I<DataVector, Dim, Frame::Inertial>>& 91 : mesh_velocity, 92 : const std::optional<Scalar<DataVector>>& div_mesh_velocity, 93 : const TimeDerivativeArguments&... time_derivative_args); 94 : } // namespace evolution::dg::Actions::detail