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/VariablesTag.hpp" 9 : #include "Evolution/Systems/GrMhd/ValenciaDivClean/BoundaryConditions/BoundaryCondition.hpp" 10 : #include "Evolution/Systems/GrMhd/ValenciaDivClean/BoundaryCorrections/BoundaryCorrection.hpp" 11 : #include "Evolution/Systems/GrMhd/ValenciaDivClean/Characteristics.hpp" 12 : #include "Evolution/Systems/GrMhd/ValenciaDivClean/ConservativeFromPrimitive.hpp" 13 : #include "Evolution/Systems/GrMhd/ValenciaDivClean/NewmanHamlin.hpp" 14 : #include "Evolution/Systems/GrMhd/ValenciaDivClean/PrimitiveFromConservative.hpp" 15 : #include "Evolution/Systems/GrMhd/ValenciaDivClean/Tags.hpp" 16 : #include "Evolution/Systems/GrMhd/ValenciaDivClean/TimeDerivativeTerms.hpp" 17 : #include "PointwiseFunctions/GeneralRelativity/Tags.hpp" 18 : #include "PointwiseFunctions/Hydro/Tags.hpp" 19 : #include "Utilities/TMPL.hpp" 20 : 21 : /// \ingroup EvolutionSystemsGroup 22 : /// \brief Items related to general relativistic magnetohydrodynamics (GRMHD) 23 : namespace grmhd { 24 : /// Items related to the Valencia formulation of ideal GRMHD with divergence 25 : /// cleaning coupled with electron fraction. 26 : /// 27 : /// References: 28 : /// - Numerical 3+1 General Relativistic Magnetohydrodynamics: A Local 29 : /// Characteristic Approach \cite Anton2006 30 : /// - GRHydro: a new open-source general-relativistic magnetohydrodynamics code 31 : /// for the Einstein toolkit \cite Moesta2014 32 : /// - Black hole-neutron star mergers with a hot nuclear equation of state: 33 : /// outflow and neutrino-cooled disk for a low-mass, high-spin case 34 : /// \cite Deaton2013 35 : /// 36 : namespace ValenciaDivClean { 37 : 38 : /*! 39 : * \brief Ideal general relativistic magnetohydrodynamics (GRMHD) system with 40 : * divergence cleaning coupled with electron fraction. 41 : * 42 : * We adopt the standard 3+1 form of metric 43 : * \f{align*} 44 : * ds^2 = -\alpha^2 dt^2 + \gamma_{ij}(dx^i + \beta^i dt)(dx^j + \beta^j dt) 45 : * \f} 46 : * where \f$\alpha\f$ is the lapse, \f$\beta^i\f$ is the shift vector, and 47 : * \f$\gamma_{ij}\f$ is the spatial metric. 48 : * 49 : * Primitive variables of the system are 50 : * - rest mass density \f$\rho\f$ 51 : * - electron fraction \f$Y_e\f$ 52 : * - the spatial velocity \f{align*} v^i = 53 : * \frac{1}{\alpha}\left(\frac{u^i}{u^0} + \beta^i\right) \f} measured by the 54 : * Eulerian observer 55 : * - specific internal energy density \f$\epsilon\f$ 56 : * - magnetic field \f$B^i = -^*F^{ia}n_a = -\alpha (^*F^{0i})\f$ 57 : * - the divergence cleaning field \f$\Phi\f$ 58 : * 59 : * with corresponding derived physical quantities which frequently appear in 60 : * equations: 61 : * - The transport velocity \f$v^i_{tr} = \alpha v^i - \beta^i\f$ 62 : * - The Lorentz factor \f{align*} W = -u^an_a = \alpha u^0 = 63 : * \frac{1}{\sqrt{1-\gamma_{ij}v^iv^j}} = \sqrt{1+\gamma^{ij}u_iu_j} = 64 : * \sqrt{1+\gamma^{ij}W^2v_iv_j} \f} 65 : * - The specific enthalpy \f$h = 1 + \epsilon + p/\rho\f$ where \f$p\f$ is the 66 : * pressure specified by a particular equation of state (EoS) 67 : * - The comoving magnetic field \f$b^b = -^*F^{ba} u_a\f$ in the ideal MHD 68 : * limit 69 : * \f{align*} 70 : * b^0 & = W B^i v_i / \alpha \\ 71 : * b^i & = (B^i + \alpha b^0 u^i) / W \\ 72 : * b^2 & = b^ab_a = B^2/W^2 + (B^iv_i)^2 73 : * \f} 74 : * - Augmented enthalpy density \f$(\rho h)^* = \rho h + b^2\f$ and augmented 75 : * pressure \f$p^* = p + b^2/2\f$ which include contributions from magnetic 76 : * field 77 : * 78 : * \note We are using the electromagnetic variables with the scaling convention 79 : * that the factor \f$4\pi\f$ does not appear in Maxwell equations and the 80 : * stress-energy tensor of the EM fields (geometrized Heaviside-Lorentz units). 81 : * To recover the physical value of magnetic field in the usual CGS Gaussian 82 : * unit, the conversion factor is 83 : * \f{align*} 84 : * \sqrt{4\pi}\frac{c^4}{G^{3/2}M_\odot} \approx 8.35 \times 10^{19} 85 : * \,\text{Gauss} 86 : * \f} 87 : * For example, magnetic field $10^{-5}$ with the code unit corresponds to the 88 : * $8.35\times 10^{14}\,\text{G}$ in the CGS Gaussian unit. See also 89 : * documentation of hydro::units::cgs::gauss_unit for details. 90 : * 91 : * The GRMHD equations can be written in a flux-balanced form 92 : * \f[ 93 : * \partial_t U+ \partial_i F^i(U) = S(U). 94 : * \f] 95 : * 96 : * Evolved (conserved) variables \f$U\f$ are 97 : * \f{align*}{ 98 : * U = \sqrt{\gamma}\left[\,\begin{matrix} 99 : * D \\ 100 : * D Y_e \\ 101 : * S_j \\ 102 : * \tau \\ 103 : * B^j \\ 104 : * \Phi \\ 105 : * \end{matrix}\,\right] \equiv \left[\,\,\begin{matrix} 106 : * \tilde{D} \\ 107 : * \tilde{Y_e} \\ 108 : * \tilde{S}_j \\ 109 : * \tilde{\tau} \\ 110 : * \tilde{B}^j \\ 111 : * \tilde{\Phi} \\ 112 : * \end{matrix}\,\,\right] = \sqrt{\gamma} \left[\,\,\begin{matrix} 113 : * \rho W \\ 114 : * \rho W Y_e \\ 115 : * (\rho h)^* W^2 v_j - \alpha b^0 b_j \\ 116 : * (\rho h)^* W^2 - p^* - (\alpha b^0)^2 - \rho W \\ 117 : * B^j \\ 118 : * \Phi \\ 119 : * \end{matrix}\,\,\right] 120 : * \f} 121 : * 122 : * where \f${\tilde D}\f$, \f${\tilde Y}_e\f$,\f${\tilde S}_i\f$, \f${\tilde 123 : * \tau}\f$, \f${\tilde B}^i\f$, and \f${\tilde \Phi}\f$ are a generalized 124 : * mass-energy density, electron fraction, momentum density, specific internal 125 : * energy density, magnetic field, and divergence cleaning field. Also, 126 : * \f$\gamma\f$ is the determinant of the spatial metric \f$\gamma_{ij}\f$. 127 : * 128 : * Corresponding fluxes \f$F^i(U)\f$ are 129 : * 130 : * \f{align*} 131 : * F^i({\tilde D}) &= {\tilde D} v^i_{tr} \\ 132 : * F^i({\tilde Y}_e) &= {\tilde Y}_e v^i_{tr} \\ 133 : * F^i({\tilde S}_j) &= {\tilde S}_j v^i_{tr} + \alpha \sqrt{\gamma} p^* 134 : * \delta^i_j - \alpha b_j \tilde{B}^i / W \\ 135 : * F^i({\tilde \tau}) &= {\tilde \tau} v^i_{tr} + \alpha \sqrt{\gamma} p^* v^i 136 : * - \alpha^2 b^0 \tilde{B}^i / W \\ 137 : * F^i({\tilde B}^j) &= {\tilde B}^j v^i_{tr} - \alpha v^j {\tilde B}^i 138 : * + \alpha \gamma^{ij} {\tilde \Phi} \\ 139 : * F^i({\tilde \Phi}) &= \alpha {\tilde B^i} - {\tilde \Phi} \beta^i 140 : * \f} 141 : * 142 : * and source terms \f$S(U)\f$ are 143 : * 144 : * \f{align*} 145 : * S({\tilde D}) &= 0 \\ 146 : * S({\tilde Y}_e) &= 0 \\ 147 : * S({\tilde S}_j) &= \frac{\alpha}{2} {\tilde S}^{mn} \partial_j \gamma_{mn} 148 : * + {\tilde S}_k \partial_j \beta^k - ({\tilde D} 149 : * + {\tilde \tau}) \partial_j \alpha \\ 150 : * S({\tilde \tau}) &= \alpha {\tilde S}^{mn} K_{mn} 151 : * - {\tilde S}^m \partial_m \alpha \\ 152 : * S({\tilde B}^j) &= -{\tilde B}^m \partial_m \beta^j 153 : * + \Phi \partial_k (\alpha \sqrt{\gamma}\gamma^{jk}) \\ 154 : * S({\tilde \Phi}) &= {\tilde B}^k \partial_k \alpha - \alpha K 155 : * {\tilde \Phi} - \alpha \kappa {\tilde \Phi} 156 : * \f} 157 : * 158 : * with 159 : * \f{align*} 160 : * {\tilde S}^{ij} = & \sqrt{\gamma} \left[ (\rho h)^* W^2 v^i v^j + p^* 161 : * \gamma^{ij} - \gamma^{ik}\gamma^{jl}b_kb_l \right] 162 : * \f} 163 : * 164 : * where \f$K\f$ is the trace of the extrinsic curvature \f$K_{ij}\f$, and 165 : * \f$\kappa\f$ is a damping parameter that damps violations of the 166 : * divergence-free (no-monopole) condition \f$\Phi = \partial_i {\tilde B}^i = 167 : * 0\f$. 168 : * 169 : * \note On the electron fraction side, the source term is currently set to 170 : * \f$S(\tilde{Y}_e) = 0\f$. Implementing the source term using neutrino scheme 171 : * is in progress (Last update : Oct 2022). 172 : * 173 : */ 174 1 : struct System { 175 0 : static constexpr bool is_in_flux_conservative_form = true; 176 0 : static constexpr bool has_primitive_and_conservative_vars = true; 177 0 : static constexpr size_t volume_dim = 3; 178 : 179 0 : using boundary_conditions_base = BoundaryConditions::BoundaryCondition; 180 0 : using boundary_correction_base = BoundaryCorrections::BoundaryCorrection; 181 : 182 0 : using variables_tag = ::Tags::Variables< 183 : tmpl::list<Tags::TildeD, Tags::TildeYe, Tags::TildeTau, Tags::TildeS<>, 184 : Tags::TildeB<>, Tags::TildePhi>>; 185 0 : using flux_variables = 186 : tmpl::list<Tags::TildeD, Tags::TildeYe, Tags::TildeTau, Tags::TildeS<>, 187 : Tags::TildeB<>, Tags::TildePhi>; 188 0 : using non_conservative_variables = tmpl::list<>; 189 0 : using gradient_variables = tmpl::list<>; 190 0 : using primitive_variables_tag = 191 : ::Tags::Variables<hydro::grmhd_tags<DataVector>>; 192 0 : using spacetime_variables_tag = 193 : ::Tags::Variables<gr::tags_for_hydro<volume_dim, DataVector>>; 194 0 : using flux_spacetime_variables_tag = ::Tags::Variables< 195 : tmpl::list<gr::Tags::Lapse<DataVector>, gr::Tags::Shift<DataVector, 3>, 196 : gr::Tags::SpatialMetric<DataVector, 3>, 197 : gr::Tags::SqrtDetSpatialMetric<DataVector>, 198 : gr::Tags::InverseSpatialMetric<DataVector, 3>>>; 199 : 200 0 : using compute_volume_time_derivative_terms = TimeDerivativeTerms; 201 : 202 0 : using conservative_from_primitive = ConservativeFromPrimitive; 203 : template <typename OrderedListOfPrimitiveRecoverySchemes> 204 0 : using primitive_from_conservative = 205 : PrimitiveFromConservative<OrderedListOfPrimitiveRecoverySchemes>; 206 : 207 0 : using compute_largest_characteristic_speed = 208 : Tags::ComputeLargestCharacteristicSpeed; 209 : 210 0 : using inverse_spatial_metric_tag = 211 : gr::Tags::InverseSpatialMetric<DataVector, volume_dim>; 212 : }; 213 : } // namespace ValenciaDivClean 214 : } // namespace grmhd