ct_emf_average.c File Reference

Collects different EMF averaging schemes. More...

#include "pluto.h"

Functions
void	CT_EMF_ArithmeticAverage (const EMF *Z1, const double w)
	Compute arithmetic average of EMF at cell edges.
void	CT_EMF_IntegrateToCorner (const Data *d, const EMF *emf, Grid *grid)
void	CT_EMF_HLL_Solver (const Data *d, const EMF *emf, Grid *grid)
	Solve 2D Riemann problem for induction equation.
void	CT_EMF_CMUSCL_Average (const Data *d, const EMF *emf, Grid *grid)
	–

Function Documentation

void CT_EMF_ArithmeticAverage	(	const EMF *	Z1,
		const double	w
	)

Combine the four electric field values computed at zone faces as upwind Godunov fluxes into an edge-centered value.
The face-centered EMF should have been stored by previous calls to CT_StoreEMF() during the one-dimensional sweeps.
This function employs a simple arithmetic averaging of the face-centered electric field.

References:

• "A Staggered Mesh Algorithm Using High Order Godunov Fluxes to Ensure Solenoidal Magnetic Fields in Magnetohydrodynamic Simulations"
  Balsara & Spicer, JCP (1999) 149, 270.

Parameters

[in]	Z1	pointer to EMF structure
[in]	w	weighting factor

Returns

This function has no return value.

Author

A. Mignone (migno.nosp@m.ne@p.nosp@m.h.uni.nosp@m.to.i.nosp@m.t)

Date

Aug 16, 31, 2012

void CT_EMF_CMUSCL_Average	(	const Data *	d,
		const EMF *	emf,
		Grid *	grid
	)

Used in the predictor scheme of CTU scheme in conjunction with UCT_HLL average. No riemann solver actually used, but only a simple pointwise average.

References:

• "A High order Godunov scheme with constrained transport and adaptie mesh refinement for astrophysical magnetohydrodynamics"
  Fromang, Hennebelle and Teyssier, A&A (2006) 457, 371

Returns

This function has no return value.

Author

A. Mignone (migno.nosp@m.ne@p.nosp@m.h.uni.nosp@m.to.i.nosp@m.t)

Date

Aug 16, 2012

void CT_EMF_HLL_Solver	(	const Data *	d,
		const EMF *	emf,
		Grid *	grid
	)

Solve 2-D Riemann problem using the 2D HLL Riemann flux formula of Londrillo & Del Zanna (2004), JCP, eq. 56. Here N, W, E, S refer to the following configuration:

*                    |
*                    N
*                 NW | NE
*                    | 
*               --W--+--E--
*                    | 
*                 SW | SE
*                    S
*                    |
* 

Parameters

[in]	d	pointer to PLUTO Data structure
[in]	grid	pointer to Grid structure;

Returns

This function has no return value.

Author

A. Mignone (migno.nosp@m.ne@p.nosp@m.h.uni.nosp@m.to.i.nosp@m.t)

Date

Aug 16, 2012

void CT_EMF_IntegrateToCorner	(	const Data *	d,
		const EMF *	emf,
		Grid *	grid
	)

Add derivatives to the 4-point arithmetic average of magnetic fields. Obtain the electric field at corners.

References:

• "An unsplit Godunov method for ideal MHD via constrained transport"
  Gardiner & Stone, JCP (2005) 205, 509. See Eq. (41), (45) and (50).

Parameters

[in]	d	pointer to PLUTO Data structure
[in]	emf	pointer to EMF structure
[in]	grid	pointer to Grid structure

Returns

This function has no return value.

Author

A. Mignone (migno.nosp@m.ne@p.nosp@m.h.uni.nosp@m.to.i.nosp@m.t)

Date

Aug 16, 31, 2012