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