IBComputeFacetVar.c File Reference

Compute the interpolated value of a provided variable on immersed body surface. More...

#include <stdio.h>
#include <stdlib.h>
#include <arrayfunctions.h>
#include <immersedboundaries.h>
#include <mpivars.h>
#include <hypar.h>

Go to the source code of this file.

Functions
int	IBComputeFacetVar (void *s, void *m, const double *const var, int nvars, double **const face_var)

Detailed Description

Compute the interpolated value of a provided variable on immersed body surface.

Author

Debojyoti Ghosh

Definition in file IBComputeFacetVar.c.

Function Documentation

IBComputeFacetVar()

int IBComputeFacetVar	(	void *	s,
		void *	m,
		const double *const	var,
		int	nvars,
		double **const	face_var
	)

Calculate the interpolated value of a provided variables on the immersed body surface: for each "local facet", i.e., facets (of the immersed body surface) that lie within the local computational domain of this MPI rank, compute the interpolated value.

The variable should be a grid variable with size/layout the same as the solution variable (HyPar::u) with the appropriate number of ghost points.

If the incoming variable has multiple components, this function will calculate interpolated value of each component.

The grad var array should be NULL at input; at output, it will point to an array of size (ImmersedBoundary::nfacets_local X nvars) that contains the interpolated value at each local facet. If there are no local facets, it will remain NULL.

The interpolation is bi/tri-linear (second-order).

Parameters

s	Solver object of type HyPar
m	MPI object of type MPIVariables
var	Variable to compute the interpolated value of
nvars	Number of components in var
face_var	Array to store the interpolated value; must be NULL at input

Definition at line 33 of file IBComputeFacetVar.c.

{
  HyPar             *solver  = (HyPar*)          s;
  MPIVariables      *mpi     = (MPIVariables*)   m; 
  ImmersedBoundary  *IB      = (ImmersedBoundary*) solver->ib;

  if (!solver->flag_ib) return(0);

  if ((*face_var) != NULL) {
    fprintf(stderr,"Error in IBComputeFacetVar()\n");
    fprintf(stderr," face_var is not NULL on rank %d\n",
            mpi->rank );
    return 1;
  }

  int nfacets_local = IB->nfacets_local;
  FacetMap *fmap = IB->fmap;

  if (nfacets_local > 0) {
    (*face_var) = (double*) calloc (nvars*nfacets_local, sizeof(double));

    for (int n = 0; n < nfacets_local; n++) {
  
      double *alpha;
      int    *nodes, j, k;
  
      double *v_c = (*face_var) + n*nvars;
      alpha = &(fmap[n].interp_coeffs[0]);
      nodes = &(fmap[n].interp_nodes[0]);
      _ArraySetValue_(v_c,nvars,0.0);
      for (j=0; j<_IB_NNODES_; j++) {
        for (k=0; k<nvars; k++) {
          v_c[k] += ( alpha[j] * var[nvars*nodes[j]+k] );
        }
      }
    }

  }

  return(0);
}