VariableFixing::FixToAtmosphere< Dim >::VelocityLimitingOptions Struct Reference

Limit the velocity in and near the atmosphere. More...

#include <FixToAtmosphere.hpp>

Classes
struct	AtmosphereDensityCutoff
struct	AtmosphereMaxVelocity
struct	NearAtmosphereMaxVelocity
struct	TransitionDensityBound

Public Types
using	options = implementation defined

Public Member Functions
void	pup (PUP::er &p)
bool	operator== (const VelocityLimitingOptions &rhs) const
bool	operator!= (const VelocityLimitingOptions &rhs) const

Public Attributes
double	atmosphere_max_velocity
double	near_atmosphere_max_velocity
double	atmosphere_density_cutoff
double	transition_density_bound

Static Public Attributes
static constexpr Options::String	help

Detailed Description

template<size_t Dim>
struct VariableFixing::FixToAtmosphere< Dim >::VelocityLimitingOptions

Limit the velocity in and near the atmosphere.

Let $v_{max}$ be the maximum magnitude of the velocity near the atmosphere, which we typically set to ${10}^{-4}$. We let $v_{\mathrm{a}\mathrm{t}\mathrm{m}}$ be the maximum magnitude of the velocity in the atmosphere, which we typically set to $0$. We then define the maximum magnitude of the spatial velocity to be

$$\begin{array}{rl}\tilde{v}& =\{\begin{array}{lll}{v}_{\mathrm{a}\mathrm{t}\mathrm{m}},& \mathrm{i}\mathrm{f}\rho <{\rho }_{v_{-}}{v}_{\mathrm{a}\mathrm{t}\mathrm{m}}+(v_{max}-v_{\mathrm{a}\mathrm{t}\mathrm{m}})\frac{\rho -{\rho }_{v_{-}}}{{\rho }_{v_{+}}-{\rho }_{v_{-}}},& \mathrm{i}\mathrm{f}{\rho }_{v_{-}}\le \rho <{\rho }_{v_{+}}\end{array}\end{array}$$

We then rescale the velocity by

$$\begin{array}{r}{v}^i\to v^i\frac{\tilde{v}}{\sqrt{v^i{\gamma }_{ij}{v}^j}}.\end{array}$$

Member Data Documentation

atmosphere_density_cutoff

template<size_t Dim>

double VariableFixing::FixToAtmosphere< Dim >::VelocityLimitingOptions::atmosphere_density_cutoff

Initial value:

{
        std::numeric_limits<double>::signaling_NaN()}

atmosphere_max_velocity

template<size_t Dim>

double VariableFixing::FixToAtmosphere< Dim >::VelocityLimitingOptions::atmosphere_max_velocity

Initial value:

{
        std::numeric_limits<double>::signaling_NaN()}

help

template<size_t Dim>

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

staticconstexpr

Initial value:

= {
        "Limit the velocity in and near the atmosphere."}

near_atmosphere_max_velocity

template<size_t Dim>

double VariableFixing::FixToAtmosphere< Dim >::VelocityLimitingOptions::near_atmosphere_max_velocity

Initial value:

{
        std::numeric_limits<double>::signaling_NaN()}

transition_density_bound

template<size_t Dim>

double VariableFixing::FixToAtmosphere< Dim >::VelocityLimitingOptions::transition_density_bound

Initial value:

{
        std::numeric_limits<double>::signaling_NaN()}

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

• src/Evolution/VariableFixing/FixToAtmosphere.hpp