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              : 
       8              : #include "DataStructures/DataBox/Tag.hpp"
       9              : #include "DataStructures/Tensor/TypeAliases.hpp"
      10              : #include "PointwiseFunctions/GeneralRelativity/TagsDeclarations.hpp"
      11              : #include "PointwiseFunctions/Hydro/TagsDeclarations.hpp"
      12              : #include "Utilities/TMPL.hpp"
      13              : 
      14              : /// \cond
      15              : namespace gsl {
      16              : template <typename>
      17              : struct not_null;
      18              : }  // namespace gsl
      19              : /// \endcond
      20              : 
      21              : namespace hydro {
      22              : /// @{
      23              : /// Computes the vector \f$J^i\f$ in \f$\dot{M} = -\int J^i s_i d^2S\f$,
      24              : /// representing the mass flux through a surface with normal \f$s_i\f$.
      25              : ///
      26              : /// Note that the integral is understood
      27              : /// as a flat-space integral: all metric factors are included in \f$J^i\f$.
      28              : /// In particular, if the integral is done over a Strahlkorper, the
      29              : /// `gr::surfaces::euclidean_area_element` of the Strahlkorper should be used,
      30              : /// and \f$s_i\f$ is
      31              : /// the normal one-form to the Strahlkorper normalized with the flat metric,
      32              : /// \f$s_is_j\delta^{ij}=1\f$.
      33              : ///
      34              : /// The formula is
      35              : /// \f$ J^i = \rho W \sqrt{\gamma}(\alpha v^i-\beta^i)\f$,
      36              : /// where \f$\rho\f$ is the mass density, \f$W\f$ is the Lorentz factor,
      37              : /// \f$v^i\f$ is the spatial velocity of the fluid,
      38              : /// \f$\gamma\f$ is the determinant of the 3-metric \f$\gamma_{ij}\f$,
      39              : /// \f$\alpha\f$ is the lapse, and \f$\beta^i\f$ is the shift.
      40              : template <typename DataType, size_t Dim, typename Frame>
      41            1 : void mass_flux(gsl::not_null<tnsr::I<DataType, Dim, Frame>*> result,
      42              :                const Scalar<DataType>& rest_mass_density,
      43              :                const tnsr::I<DataType, Dim, Frame>& spatial_velocity,
      44              :                const Scalar<DataType>& lorentz_factor,
      45              :                const Scalar<DataType>& lapse,
      46              :                const tnsr::I<DataType, Dim, Frame>& shift,
      47              :                const Scalar<DataType>& sqrt_det_spatial_metric);
      48              : 
      49              : template <typename DataType, size_t Dim, typename Frame>
      50            1 : tnsr::I<DataType, Dim, Frame> mass_flux(
      51              :     const Scalar<DataType>& rest_mass_density,
      52              :     const tnsr::I<DataType, Dim, Frame>& spatial_velocity,
      53              :     const Scalar<DataType>& lorentz_factor, const Scalar<DataType>& lapse,
      54              :     const tnsr::I<DataType, Dim, Frame>& shift,
      55              :     const Scalar<DataType>& sqrt_det_spatial_metric);
      56              : /// @}
      57              : 
      58              : namespace Tags {
      59              : /// Compute item for mass flux vector \f$J^i\f$.
      60              : ///
      61              : /// Can be retrieved using `hydro::Tags::MassFlux`
      62              : template <typename DataType, size_t Dim, typename Frame>
      63            1 : struct MassFluxCompute : MassFlux<DataType, Dim, Frame>,
      64              :                                db::ComputeTag {
      65            0 :   using argument_tags =
      66              :       tmpl::list<hydro::Tags::RestMassDensity<DataType>,
      67              :                  hydro::Tags::SpatialVelocity<DataType, Dim, Frame>,
      68              :                  hydro::Tags::LorentzFactor<DataType>,
      69              :                  ::gr::Tags::Lapse<DataType>,
      70              :                  ::gr::Tags::Shift<DataType, Dim, Frame>,
      71              :                  ::gr::Tags::SqrtDetSpatialMetric<DataType>>;
      72              : 
      73            0 :   using return_type = tnsr::I<DataType, Dim, Frame>;
      74              : 
      75            0 :   static constexpr auto function = static_cast<void (*)(
      76              :       gsl::not_null<tnsr::I<DataType, Dim, Frame>*>, const Scalar<DataType>&,
      77              :       const tnsr::I<DataType, Dim, Frame>&, const Scalar<DataType>&,
      78              :       const Scalar<DataType>&, const tnsr::I<DataType, Dim, Frame>&,
      79              :       const Scalar<DataType>&)>(&mass_flux<DataType, Dim, Frame>);
      80              : 
      81            0 :   using base = MassFlux<DataType, Dim, Frame>;
      82              : };
      83              : }  // namespace Tags
      84              : }  // namespace hydro