Line data    Source code

       1            0 : // Distributed under the MIT License.
       2              : // See LICENSE.txt for details.
       3              : 
       4              : #pragma once
       5              : 
       6              : #include <memory>
       7              : #include <optional>
       8              : 
       9              : #include "DataStructures/DataBox/Prefixes.hpp"
      10              : #include "DataStructures/Tensor/TypeAliases.hpp"
      11              : #include "Evolution/BoundaryCorrection.hpp"
      12              : #include "Evolution/Systems/Burgers/Tags.hpp"
      13              : #include "NumericalAlgorithms/DiscontinuousGalerkin/Formulation.hpp"
      14              : #include "Options/String.hpp"
      15              : #include "Utilities/Serialization/CharmPupable.hpp"
      16              : #include "Utilities/TMPL.hpp"
      17              : 
      18              : /// \cond
      19              : class DataVector;
      20              : namespace gsl {
      21              : template <typename T>
      22              : class not_null;
      23              : }  // namespace gsl
      24              : namespace PUP {
      25              : class er;
      26              : }  // namespace PUP
      27              : /// \endcond
      28              : 
      29              : namespace Burgers::BoundaryCorrections {
      30              : /*!
      31              :  * \brief An HLL (Harten-Lax-van Leer) Riemann solver
      32              :  *
      33              :  * Let \f$U\f$ be the evolved variable, \f$F^i\f$ the flux, and \f$n_i\f$ be
      34              :  * the outward directed unit normal to the interface. Denoting \f$F := n_i
      35              :  * F^i\f$, the HLL boundary correction is \cite Harten1983
      36              :  *
      37              :  * \f{align*}
      38              :  * G_\text{HLL} = \frac{\lambda_\text{max} F_\text{int} +
      39              :  * \lambda_\text{min} F_\text{ext}}{\lambda_\text{max} - \lambda_\text{min}}
      40              :  * - \frac{\lambda_\text{min}\lambda_\text{max}}{\lambda_\text{max} -
      41              :  * \lambda_\text{min}} \left(U_\text{int} - U_\text{ext}\right)
      42              :  * \f}
      43              :  *
      44              :  * where "int" and "ext" stand for interior and exterior, and \cite Davis1988
      45              :  *
      46              :  * \f{align*}
      47              :  * \lambda_\text{min} &= \text{min}\left(U_\text{int},-U_\text{ext}, 0\right) \\
      48              :  * \lambda_\text{max} &= \text{max}\left(U_\text{int},-U_\text{ext}, 0\right),
      49              :  * \f}
      50              :  *
      51              :  * The positive sign in front of the \f$F_{\text{ext}}\f$ in \f$G_\text{HLL}\f$
      52              :  * and the minus signs in front of the \f$U_\text{ext}\f$ terms in
      53              :  * \f$\lambda_\text{min}\f$ and \f$\lambda_\text{max}\f$ terms are necessary
      54              :  * because the outward directed normal of the neighboring element has the
      55              :  * opposite sign, i.e. \f$n_i^{\text{ext}}=-n_i^{\text{int}}\f$. Note that for
      56              :  * either \f$\lambda_\text{min} = 0\f$ or \f$\lambda_\text{max} = 0\f$ (i.e. all
      57              :  * characteristics move in the same direction) the HLL boundary correction
      58              :  * reduces to pure upwinding.
      59              :  *
      60              :  * \note
      61              :  * - In the strong form the `dg_boundary_terms` function returns
      62              :  * \f$G - F_\text{int}\f$
      63              :  * - Some references use \f$S\f$ instead of \f$\lambda\f$ for the
      64              :  * signal/characteristic speeds
      65              :  */
      66            1 : class Hll final : public evolution::BoundaryCorrection {
      67              :  private:
      68            0 :   struct CharSpeed : db::SimpleTag {
      69            0 :     using type = Scalar<DataVector>;
      70              :   };
      71              : 
      72              :  public:
      73            0 :   using options = tmpl::list<>;
      74            0 :   static constexpr Options::String help = {
      75              :       "Computes the HLL boundary correction term for the Burgers system."};
      76              : 
      77            0 :   Hll() = default;
      78            0 :   Hll(const Hll&) = default;
      79            0 :   Hll& operator=(const Hll&) = default;
      80            0 :   Hll(Hll&&) = default;
      81            0 :   Hll& operator=(Hll&&) = default;
      82            0 :   ~Hll() override = default;
      83              : 
      84              :   /// \cond
      85              :   explicit Hll(CkMigrateMessage* msg);
      86              :   using PUP::able::register_constructor;
      87              :   WRAPPED_PUPable_decl_template(Hll);  // NOLINT
      88              :   /// \endcond
      89            0 :   void pup(PUP::er& p) override;  // NOLINT
      90              : 
      91            0 :   std::unique_ptr<BoundaryCorrection> get_clone() const override;
      92              : 
      93            0 :   using dg_package_field_tags =
      94              :       tmpl::list<Tags::U, ::Tags::NormalDotFlux<Tags::U>, CharSpeed>;
      95            0 :   using dg_package_data_temporary_tags = tmpl::list<>;
      96            0 :   using dg_package_data_volume_tags = tmpl::list<>;
      97            0 :   using dg_boundary_terms_volume_tags = tmpl::list<>;
      98              : 
      99            0 :   static double dg_package_data(
     100              :       gsl::not_null<Scalar<DataVector>*> packaged_u,
     101              :       gsl::not_null<Scalar<DataVector>*> packaged_normal_dot_flux,
     102              :       gsl::not_null<Scalar<DataVector>*> packaged_char_speed,
     103              :       const Scalar<DataVector>& u,
     104              :       const tnsr::I<DataVector, 1, Frame::Inertial>& flux_u,
     105              :       const tnsr::i<DataVector, 1, Frame::Inertial>& normal_covector,
     106              :       const std::optional<tnsr::I<DataVector, 1, Frame::Inertial>>&
     107              :           mesh_velocity,
     108              :       const std::optional<Scalar<DataVector>>& normal_dot_mesh_velocity);
     109              : 
     110            0 :   static void dg_boundary_terms(
     111              :       gsl::not_null<Scalar<DataVector>*> boundary_correction_u,
     112              :       const Scalar<DataVector>& u_int,
     113              :       const Scalar<DataVector>& normal_dot_flux_u_int,
     114              :       const Scalar<DataVector>& abs_char_speed_int,
     115              :       const Scalar<DataVector>& u_ext,
     116              :       const Scalar<DataVector>& normal_dot_flux_u_ext,
     117              :       const Scalar<DataVector>& abs_char_speed_ext,
     118              :       dg::Formulation dg_formulation);
     119              : };
     120              : }  // namespace Burgers::BoundaryCorrections