BoundaryIntegral.c File Reference

Compute the flux integral over the physical boundary. More...

#include <stdlib.h>
#include <basic.h>
#include <arrayfunctions.h>
#include <mpivars.h>
#include <hypar.h>

Go to the source code of this file.

Functions
int	BoundaryIntegral (void *s, void *m)

Detailed Description

Compute the flux integral over the physical boundary.

Author

Debojyoti Ghosh

Definition in file BoundaryIntegral.c.

Function Documentation

int BoundaryIntegral	(	void *	s,
		void *	m
	)

Computes the flux integral over the boundary. The local flux integral (on this processor) is computed for physical as well as MPI boundaries. The global boundary integral is computed by summing the local integrals over all the processors, since the contributions from the MPI boundaries cancel out.

Parameters

s	Solver object of type HyPar
m	MPI object of type MPIVariables

Definition at line 17 of file BoundaryIntegral.c.

{
  HyPar         *solver = (HyPar*)        s;
  MPIVariables  *mpi    = (MPIVariables*) m;

  int ndims   = solver->ndims;
  int nvars   = solver->nvars;
  int *dim    = solver->dim_local;
  int ghosts  = solver->ghosts;
  int d,v,k;

  double *local_integral  = (double*) calloc (nvars,sizeof(double));
  double *global_integral = (double*) calloc (nvars,sizeof(double));

  /* calculate the local boundary integral on each process */
  _ArraySetValue_(local_integral,nvars,0.0);
  for (d=0; d<ndims; d++) {
    for (v=0; v<nvars; v++) {
      double dxinv[ndims], dS = 1.0; 
      for (k=0; k<ndims; k++) { 
        /* uniform grid assumed */
        _GetCoordinate_(k,dim[k]/2,dim,ghosts,solver->dxinv,dxinv[k]); 
      }
      for (k=0; k<ndims; k++) if (k!=d) dS *= (1.0/dxinv[k]);
      local_integral[v] += (solver->StepBoundaryIntegral[(2*d+0)*nvars+v])*dS;
      local_integral[v] += (solver->StepBoundaryIntegral[(2*d+1)*nvars+v])*dS;
    }
  }

  /* add across process to calculate global boundary integral 
   * (internal (MPI) boundaries must cancel out)
   */
  IERR MPISum_double(global_integral,local_integral,nvars,&mpi->world); CHECKERR(ierr);

  /* add to the total boundary integral */
  _ArrayAXPY_(global_integral,1.0,solver->TotalBoundaryIntegral,nvars);

  free(local_integral);
  free(global_integral);
  return(0);
}