BCNoFlux.c File Reference

No-flux boundary condition (specific to Numa2D and Numa3D). More...

#include <stdlib.h>
#include <basic.h>
#include <arrayfunctions.h>
#include <boundaryconditions.h>
#include <physicalmodels/numa2d.h>
#include <physicalmodels/numa3d.h>

Go to the source code of this file.

Functions
int	BCNoFluxU (void *b, void *m, int ndims, int nvars, int *size, int ghosts, double *phi, double waqt)

Detailed Description

No-flux boundary condition (specific to Numa2D and Numa3D).

Author

Debojyoti Ghosh

Definition in file BCNoFlux.c.

Function Documentation

BCNoFluxU()

int BCNoFluxU	(	void *	b,
		void *	m,
		int	ndims,
		int	nvars,
		int *	size,
		int	ghosts,
		double *	phi,
		double	waqt
	)

Applies the no-flux boundary conditions: This boundary condition is specific to the NUMA 2D/3D (Numa2D, Numa3D). Used for simulating inviscid walls or symmetry boundaries. It's equivalent to the slip-wall BC of the Euler/Navier- Stokes system.

The density, potential temperature, and tangential velocity are extrapolated, while the normal velocity at the ghost point is set to the negative of that in the interior (to enforce zero-normal velocity at the boundary face).

Parameters

b	Boundary object of type DomainBoundary
m	MPI object of type MPIVariables
ndims	Number of spatial dimensions
nvars	Number of variables/DoFs per grid point
size	Integer array with the number of grid points in each spatial dimension
ghosts	Number of ghost points
phi	The solution array on which to apply the boundary condition
waqt	Current solution time

Definition at line 22 of file BCNoFlux.c.

{
  DomainBoundary *boundary = (DomainBoundary*) b;

  int dim   = boundary->dim;
  int face  = boundary->face;

  if (boundary->on_this_proc) {
    int bounds[ndims], indexb[ndims], indexi[ndims];
    _ArraySubtract1D_ (bounds,boundary->ie,boundary->is,ndims);
    _ArraySetValue_   (indexb,ndims,0);
    int done = 0;
    while (!done) {
      int p1, p2;
      _ArrayCopy1D_ (indexb,indexi,ndims);
      _ArrayAdd1D_  (indexi,indexi,boundary->is,ndims);
      if      (face ==  1) indexi[dim] = ghosts-1-indexb[dim];
      else if (face == -1) indexi[dim] = size[dim]-indexb[dim]-1;
      else return(1);
      _ArrayIndex1DWO_  (ndims,size,indexb,boundary->is,ghosts,p1);
      _ArrayIndex1D_    (ndims,size,indexi,ghosts,p2);
      
      if (nvars == 4) {
        phi[nvars*p1+0] = phi[nvars*p2+0];
        phi[nvars*p1+1] = (dim == _XDIR_ ? -phi[nvars*p2+1] : phi[nvars*p2+1] );
        phi[nvars*p1+2] = (dim == _YDIR_ ? -phi[nvars*p2+2] : phi[nvars*p2+2] );
        phi[nvars*p1+3] = phi[nvars*p2+3];
      } else if (nvars == 5) {
        phi[nvars*p1+0] = phi[nvars*p2+0];
        phi[nvars*p1+1] = (dim == _XDIR_ ? -phi[nvars*p2+1] : phi[nvars*p2+1] );
        phi[nvars*p1+2] = (dim == _YDIR_ ? -phi[nvars*p2+2] : phi[nvars*p2+2] );
        phi[nvars*p1+3] = (dim == _ZDIR_ ? -phi[nvars*p2+3] : phi[nvars*p2+3] );
        phi[nvars*p1+4] = phi[nvars*p2+4];
      }

      _ArrayIncrementIndex_(ndims,bounds,indexb,done);
    }
  }
  return(0);
}