BackwardsRK2 Class Reference

#include <backwardsRK.h>

Inheritance diagram for BackwardsRK2:

Collaboration diagram for BackwardsRK2:

Public Member Functions
	BackwardsRK2 (Data *data, Model *model, Bcs *bcs, FluxMethod *fluxMethod)
virtual	~BackwardsRK2 ()
void	step (double *cons, double *prims, double *aux, double dt=0)
Public Member Functions inherited from RKSplit
	RKSplit (Data *data, Model *model, Bcs *bcs, FluxMethod *fluxMethod, ModelExtension *modelExtension=NULL)
virtual	~RKSplit ()
Public Member Functions inherited from RK2
	RK2 (Data *data, Model *model, Bcs *bcs, FluxMethod *fluxMethod, ModelExtension *modelExtension=NULL)
virtual	~RK2 ()
void	predictorStep (double *cons, double *prims, double *aux, double dt)
void	correctorStep (double *cons, double *prims, double *aux, double dt)
void	step (double *cons, double *prims, double *aux, double dt=0)
Public Member Functions inherited from TimeIntegrator
	TimeIntegrator (Data *data, Model *model, Bcs *bcs, FluxMethod *fluxMethod, ModelExtension *modelExtension=NULL)
virtual	~TimeIntegrator ()
void	finalise (double *cons, double *prims, double *aux)
Public Member Functions inherited from TimeIntegratorBase
	TimeIntegratorBase (Data *data, Model *model, Bcs *bcs, FluxMethod *fluxMethod, ModelExtension *modelExtension=NULL)
virtual	~TimeIntegratorBase ()

Public Attributes
BackRKArguments	args
Public Attributes inherited from RK2
double *	p1cons
double *	p1prims
double *	p1aux
double *	args1
double *	args2
Public Attributes inherited from TimeIntegratorBase
Data *	data
Model *	model
Bcs *	bcs
FluxMethod *	fluxMethod
ModelExtension *	modelExtension

Detailed Description

Semi-implicit second order Runge-Kutta time integrator

Integrator deals with the flux contribution explicitly and the source terms implicitly. Soecifically, the explicit step is performed by a second order RK method, and the implicit is a backwards euler formulism.

The form of the forward step is TVD second order RK2. Such that the intermediate state due to the flux contribution is

\begin{align} U^* = RK2(U^n) \end{align}

with the source contribution determined via a backwards Euler step,

\begin{align} U^{n+1} = U^* + \Psi(U^{n+1}) \end{align}

where \(\Psi(U)\) is the source vector due to the conserved vector \(U\).

The backwards step is solved using a multidimensional newton secant method, which we've implemented using the hydr1 rootfinder available here.

See also

RK2

Definition at line 29 of file backwardsRK.h.

Constructor & Destructor Documentation

BackwardsRK2()

BackwardsRK2::BackwardsRK2	(	Data *	data,
		Model *	model,
		Bcs *	bcs,
		FluxMethod *	fluxMethod
	)

Constructor.

Constructor requires simulation data and the flux and source functions from the model class.

Parameters

[in]	*data	Pointer to Data class containing global simulation data
[in]	*model	pointer to Model object
[in]	*bcs	pointer to Bcs object
[in]	*fluxMethod	pointer to FluxMethod object

See also

TimeIntegrator::TimeIntegrator

RK2::RK2

RKSplit::RKSplit

~BackwardsRK2()

virtual BackwardsRK2::~BackwardsRK2 ( )

inlinevirtual

Destructor.

Definition at line 50 of file backwardsRK.h.

Member Function Documentation

step()

void BackwardsRK2::step ( double *  cons, double *  prims, double *  aux, double  dt = 0  )

virtual

Performs a single time step.

The timestep will use the current values of the conserved, primitive and auxiliary variables at t=t0 and compute the values of all of them at time \(t=t0 + dt\). I.e. the conserved vector is evolved forward, and the corresponding prims and aux vars are found.

Parameters

[in,out]	*cons	pointer to conserved vector work array. Size is \(N_{cons} \times N_x \times N_y \times N_z\)
[in,out]	*prims	pointer to primitive vector work array. Size is \(N_{prims} \times N_x \times N_y \times N_z\)
[in,out]	*aux	pointer to auxiliary vector work array. Size is \(N_{aux} \times N_x \times N_y \times N_z\)
[in]	dt	the step size desired to move by. Defaults to the value in the Data class

See also

TimeIntegrator::step

RK2::step

RKSplit::step

Implements TimeIntegratorBase.

Member Data Documentation

args

BackRKArguments BackwardsRK2::args

BackRKArguments, additional arguments class.

Definition at line 33 of file backwardsRK.h.

---

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

• backwardsRK.h