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 = tmpl::list< AtmosphereMaxVelocity, NearAtmosphereMaxVelocity, AtmosphereDensityCutoff, TransitionDensityBound >

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 \(v_{\mathrm{atm}}\) 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{align*} \tilde{v} &=\begin{cases} v_{\mathrm{atm}}, & \mathrm{if}\; \rho < \rho_{v_-} \ \ v_{\mathrm{atm}} + \left(v_{\max} - v_{\mathrm{atm}}\right) \frac{\rho - \rho_{v_-}}{\rho_{v_+} - \rho_{v_-}}, & \mathrm{if}\;\rho_{v_-} \le \rho < \rho_{v_+} \end{cases} \end{align*}

We then rescale the velocity by

\begin{align*} v^i\to v^i\frac{\tilde{v}}{\sqrt{v^i\gamma_{ij}v^j}}. \end{align*}

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