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 <limits>
       8              : #include <optional>
       9              : #include <string>
      10              : 
      11              : 
      12              : /// \cond
      13              : namespace EquationsOfState {
      14              : template <bool, size_t>
      15              : class EquationOfState;
      16              : }  // namespace EquationsOfState
      17              : namespace grmhd::ValenciaDivClean {
      18              : class PrimitiveFromConservativeOptions;
      19              : }  // namespace grmhd::ValenciaDivClean
      20              : /// \endcond
      21              : 
      22              : namespace grmhd::ValenciaDivClean::PrimitiveRecoverySchemes {
      23              : 
      24              : struct PrimitiveRecoveryData;
      25              : 
      26              : /*!
      27              :  * \brief Compute the primitive variables from the conservative variables using
      28              :  * the scheme of \cite Galeazzi2013mia.
      29              :  *
      30              :  * In the notation of the Kastaun paper, `tau` is \f$D q\f$,
      31              :  * `momentum_density_squared` is \f$r^2 D^2\f$,
      32              :  * `rest_mass_density_times_lorentz_factor` is \f$D\f$.
      33              :  * Furthermore, the algorithm iterates over \f$z\f$, which is the Lorentz factor
      34              :  * times the absolute magnetitude of the velocity.
      35              :  *
      36              :  * In terms of the conservative variables (in our notation):
      37              :  * \f{align*}
      38              :  * q = & \frac{{\tilde \tau}}{{\tilde D}} \\
      39              :  * r^2 = & \frac{\gamma^{kl} {\tilde S}_k {\tilde S}_l}{{\tilde D}^2} \\
      40              :  * \f}
      41              :  *
      42              :  * where the conserved variables \f${\tilde D}\f$, \f${\tilde S}_i\f$ and
      43              :  * \f${\tilde \tau}\f$ are a generalized mass-energy
      44              :  * density, momentum density and specific internal energy density,
      45              :  * and \f$\gamma\f$ and \f$\gamma^{kl}\f$ are the determinant and inverse
      46              :  * of the spatial metric \f$\gamma_{kl}\f$.
      47              :  *
      48              :  * \note This scheme does not use the initial guess for the pressure.
      49              :  */
      50            1 : class KastaunEtAlHydro {
      51              :  public:
      52              :   template <bool EnforcePhysicality, typename EosType>
      53            0 :   static std::optional<PrimitiveRecoveryData> apply(
      54              :       double initial_guess_pressure, double tau,
      55              :       double momentum_density_squared,
      56              :       double momentum_density_dot_magnetic_field, double magnetic_field_squared,
      57              :       double rest_mass_density_times_lorentz_factor, double electron_fraction,
      58              :       const EosType& equation_of_state,
      59              :       const grmhd::ValenciaDivClean::PrimitiveFromConservativeOptions&
      60              :           primitive_from_conservative_options);
      61              : 
      62            0 :   static const std::string name() { return "KastaunEtAlHydro"; }
      63              : 
      64              :  private:
      65            0 :   static constexpr size_t max_iterations_ = 100;
      66            0 :   static constexpr double absolute_tolerance_ =
      67              :       10.0 * std::numeric_limits<double>::epsilon();
      68            0 :   static constexpr double relative_tolerance_ =
      69              :       10.0 * std::numeric_limits<double>::epsilon();
      70              : };
      71              : }  // namespace grmhd::ValenciaDivClean::PrimitiveRecoverySchemes