boundary.c File Reference

Set boundary conditions. More...

#include "pluto.h"

Functions
void	Boundary (const Data *d, int idim, Grid *grid)
void	OutflowBound (double ***q, RBox *box, int side, Grid *grid)
void	FlipSign (int side, int type, int *vsign)
void	ReflectiveBound (double ***q, RBox *box, int s, int side)
void	PeriodicBound (double ***q, RBox *box, int side)

Detailed Description

The Boundary() function sets both internal and physical boundary conditions on one or more sides of the computational domain. It is used to fill ghost zones of both cell-centered and face-centered data arrays.
The type of boundary conditions at the leftmost or rightmost side of a given grid is specified by the integers grid[dir].lbound or grid[dir].rbound , respectively. When this value is different from zero, the local processor borders the physical boundary and the admissible values for lbound or rbound are OUTFLOW, REFLECTIVE, AXISYMMETRIC, EQTSYMMETRIC, PERIODIC, SHEARING or USERDEF. Conversely, when this value is zero (internal boundary), two neighboring processors that share the same side need to fill ghost zones by exchanging data values. This step is done here only for parallel computations on static grids.

Predefined physical boundary conditions are handled by the following functions:

• OutflowBound()
• ReflectiveBound()
• PeriodicBound()

Author

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

Date

Nov 5, 2012

Function Documentation

void Boundary	(	const Data *	d,
		int	idim,
		Grid *	grid
	)

Set boundary conditions on one or more sides of the computational domain.

Parameters

[in,out]	d	pointer to PLUTO Data structure containing the solution array (including centered and staggered fields)
[in]	idim	specifies on which side(s) of the computational domain boundary conditions must be set. Possible values are idim = IDIR first dimension (x1) idim = JDIR second dimenson (x2) idim = KDIR third dimension (x3) idim = ALL_DIR all dimensions
[in]	grid	pointer to an array of grid structures.

void FlipSign	(	int	side,
		int	type,
		int *	vsign
	)

Reverse the sign of vector components with respect to axis side. Depending on type, one needs to symmetrize or anti-symmetrize:

• REFLECTIVE:
  o Vn -> -Vn, Bn -> -Bn
  o Vp -> Vp, Bp -> Bp
  o Vt -> Vt, Bt -> Bt

• AXISYMMETRIC:
  o Vn -> -Vn, Bn -> -Bn
  o Vp -> Vp, Bp -> Bp
  o Vt -> -Vt, Bt -> -Bt

• EQTSYMMETRIC:
  o Vn -> -Vn, Bn -> Bn
  o Vp -> Vp, Bp -> -Bp
  o Vt -> Vt, Bt -> -Bt

where (n) is the normal components, (p) and (t) are the transverse (or poloidal and toroidal for cylindrical and spherical coordinates) components.

Parameters

[in]	side	boundary side
[in]	type	boundary condition type
[out]	vsign	an array of values (+1 or -1) giving the sign

void OutflowBound	(	double ***	q,
		RBox *	box,
		int	side,
		Grid *	grid
	)

Impose zero-gradient boundary conditions on 'q' on the boundary side specified by box->side. The staggered component of magnetic field is assigned using the div.B = 0 condition in a different loop.

Parameters

[in,out]	q	a 3D array representing a flow variable
[in]	box	pointer to a RBox structure defining the extent of the boundary region and the variable position inside the cell
[in]	grid	pointer to an array of Grid structures

void PeriodicBound	(	double ***	q,
		RBox *	box,
		int	side
	)

Implements periodic boundary conditions.

void ReflectiveBound	(	double ***	q,
		RBox *	box,
		int	s,
		int	side
	)

Make symmetric (s = 1) or anti-symmetric (s=-1) variable profiles with respect to coordinate axis specified by box->side. The sign is set by the FlipSign() function.

Parameters

[in,out]	q	a 3D flow quantity
[in]	box	pointer to box structure
[in]	s	an integer taking only the values +1 (symmetric profile) or -1 (antisymmetric profile)