Variable Fixing

A collection of different variable fixers ranging in sophistication. More...

Classes
class	grmhd::ValenciaDivClean::FixConservatives
	Fix conservative variables using method developed by Foucart. More...
struct	VariableFixing::Actions::FixVariables< VariableFixer >
	Adjust variables with a variable fixer. More...
class	VariableFixing::FixToAtmosphere< Dim >
	Fix the primitive variables to an atmosphere in low density regions. More...
class	VariableFixing::LimitLorentzFactor
	Limit the maximum Lorentz factor to LorentzFactorCap in regions where the density is below MaxDensityCutoff. More...
class	VariableFixing::ParameterizedDeleptonization
	Adjust the electron fraction (Ye) based on rest mass density (rho). More...
class	VariableFixing::RadiallyFallingFloor< Dim >
	Applies a pressure and density floor dependent on the distance to the origin. More...

Detailed Description

A collection of different variable fixers ranging in sophistication.

Build-up of numerical error can cause physical quantities to evolve toward non-physical values. For example, pressure and density may become negative. This will subsequently lead to failures in numerical inversion schemes to recover the corresponding convervative values. A rough fix that enforces physical quantities stay physical is to simply change them by hand when needed. This can be done at various degrees of sophistication, but in general the fixed quantities make up a negligible amount of the physics of the simulation; a rough fix is vastly preferred to a simulation that fails to complete due to nonphysical quantities.