VariableFixing::FixToAtmosphere< Dim > Class Template Reference

Fix the primitive variables to an atmosphere in low density regions. More...

#include <FixToAtmosphere.hpp>

Classes
struct	DensityCutoff
	Rest mass density at which to impose the atmosphere. Should be greater than or equal to the density of the atmosphere. More...
struct	DensityOfAtmosphere
	Rest mass density of the atmosphere. More...
struct	MaxVelocityMagnitude
	The maximum magnitude of the velocity when the density is below TransitionDensityCutoff More...
struct	TransitionDensityCutoff
	For densities between DensityOfAtmosphere and TransitionDensityCutoff the velocity is transitioned away from atmosphere to avoid abrupt cutoffs. More...

Public Types
using	options = tmpl::list< DensityOfAtmosphere, DensityCutoff, TransitionDensityCutoff, MaxVelocityMagnitude >
using	return_tags = tmpl::list< hydro::Tags::RestMassDensity< DataVector >, hydro::Tags::SpecificInternalEnergy< DataVector >, hydro::Tags::SpatialVelocity< DataVector, Dim >, hydro::Tags::LorentzFactor< DataVector >, hydro::Tags::Pressure< DataVector >, hydro::Tags::Temperature< DataVector > >
using	argument_tags = tmpl::list< hydro::Tags::ElectronFraction< DataVector >, gr::Tags::SpatialMetric< DataVector, Dim >, hydro::Tags::EquationOfStateBase >

Public Member Functions
	FixToAtmosphere (double density_of_atmosphere, double density_cutoff, double transition_density_cutoff, double max_velocity_magnitude, const Options::Context &context={})
	FixToAtmosphere (const FixToAtmosphere &)=default
FixToAtmosphere &	operator= (const FixToAtmosphere &)=default
	FixToAtmosphere (FixToAtmosphere &&)=default
FixToAtmosphere &	operator= (FixToAtmosphere &&)=default
void	pup (PUP::er &p)
template<size_t ThermodynamicDim>
void	operator() (gsl::not_null< Scalar< DataVector > * > rest_mass_density, gsl::not_null< Scalar< DataVector > * > specific_internal_energy, gsl::not_null< tnsr::I< DataVector, Dim, Frame::Inertial > * > spatial_velocity, gsl::not_null< Scalar< DataVector > * > lorentz_factor, gsl::not_null< Scalar< DataVector > * > pressure, gsl::not_null< Scalar< DataVector > * > temperature, const Scalar< DataVector > &electron_fraction, const tnsr::ii< DataVector, Dim, Frame::Inertial > &spatial_metric, const EquationsOfState::EquationOfState< true, ThermodynamicDim > &equation_of_state) const

Static Public Attributes
static constexpr Options::String	help

Friends
template<size_t SpatialDim>
bool	operator== (const FixToAtmosphere< SpatialDim > &lhs, const FixToAtmosphere< SpatialDim > &rhs)

Detailed Description

template<size_t Dim>
class VariableFixing::FixToAtmosphere< Dim >

Fix the primitive variables to an atmosphere in low density regions.

If the rest mass density is below \(\rho_{\textrm{cutoff}}\) (DensityCutoff), it is set to \(\rho_{\textrm{atm}}\) (DensityOfAtmosphere), and the pressure, and specific internal energy (for one-dimensional equations of state) are adjusted to satisfy the equation of state. For a two-dimensional equation of state, the specific internal energy is set to zero. In addition, the spatial velocity is set to zero, and the Lorentz factor is set to one.

If the rest mass density is above \(\rho_{\textrm{cutoff}}\) but below \(\rho_{\textrm{transition}}\) (TransitionDensityCutoff) then the velocity is rescaled such that

\begin{align*} \sqrt{v^i v_i}\le \frac{(\rho-\rho_{\textrm{cutoff}})} {(\rho_{\textrm{transition}} - \rho_{\textrm{cutoff}})} v_{\max} \end{align*}

where \(v_{\max}\) (MaxVelocityMagnitude) is the maximum allowed magnitude of the velocity. This prescription follows Appendix 2.d of [135] Note that we require \(\rho_{\textrm{transition}}\in(\rho_{\textrm{cutoff}}, 10\rho_{\textrm{atm}}]\)

Member Data Documentation

help

template<size_t Dim>

constexpr Options::String VariableFixing::FixToAtmosphere< Dim >::help

staticconstexpr

Initial value:

= {
      "If the rest mass density is below DensityCutoff, it is set\n"
      "to DensityOfAtmosphere, and the pressure, and specific internal energy\n"
      "(for one-dimensional equations of state) are\n"
      "adjusted to satisfy the equation of state. For a two-dimensional\n"
      "equation of state, the specific internal energy is set to zero.\n"
      "In addition, the spatial velocity is set to zero, and the Lorentz\n"
      "factor is set to one.\n"}

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The documentation for this class was generated from the following file:

• src/Evolution/VariableFixing/FixToAtmosphere.hpp