HyperbolicFunction.c

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#include <time.h>

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

static int ReconstructHyperbolic (double*,double*,double*,double*,int,void*,void*,double,int,
                                 int(*)(double*,double*,double*,double*,double*,double*,int,void*,double));
static int DefaultUpwinding      (double*,double*,double*,double*,double*,double*,int,void*,double);

int HyperbolicFunction(
                        double  *hyp, 
                        double  *u,   
                        void    *s,   
                        void    *m,   
                        double  t,    
                        int     LimFlag,  
                        int(*FluxFunction)(double*,double*,int,void*,double),
                        int(*UpwindFunction)(double*,double*,double*,double*,double*,double*,int,void*,double)
                      )
{
  HyPar         *solver = (HyPar*)        s;
  MPIVariables  *mpi    = (MPIVariables*) m;
  int           d, v, i, done;
  double        *FluxI  = solver->fluxI; /* interface flux     */
  double        *FluxC  = solver->fluxC; /* cell centered flux */
  _DECLARE_IERR_;

  int     ndims  = solver->ndims;
  int     nvars  = solver->nvars;
  int     ghosts = solver->ghosts;
  int     *dim   = solver->dim_local;
  int     size   = solver->npoints_local_wghosts;
  double  *x     = solver->x;
  double  *dxinv = solver->dxinv;
  int     index[ndims], index1[ndims], index2[ndims], dim_interface[ndims];

  LimFlag = (LimFlag && solver->flag_nonlinearinterp && solver->SetInterpLimiterVar);

  _ArraySetValue_(hyp,size*nvars,0.0);
  _ArraySetValue_(solver->StageBoundaryIntegral,2*ndims*nvars,0.0);
  if (!FluxFunction) return(0); /* zero hyperbolic term */
  solver->count_hyp++;

#if defined(CPU_STAT)
  double cpu_time = 0.0;
  clock_t cpu_start, cpu_end;
#endif

  int offset = 0;
  for (d = 0; d < ndims; d++) {
    _ArrayCopy1D_(dim,dim_interface,ndims); dim_interface[d]++;
    int size_cellcenter = 1; for (i = 0; i < ndims; i++) size_cellcenter *= (dim[i] + 2*ghosts);
    int size_interface = 1; for (i = 0; i < ndims; i++) size_interface *= dim_interface[i];

    /* evaluate cell-centered flux */
    IERR FluxFunction(FluxC,u,d,solver,t); CHECKERR(ierr);
    /* compute interface fluxes */
    IERR ReconstructHyperbolic(FluxI,FluxC,u,x+offset,d,solver,mpi,t,LimFlag,UpwindFunction);
    CHECKERR(ierr);

    /* calculate the first derivative */
    done = 0; _ArraySetValue_(index,ndims,0);
    int p, p1, p2;

#if defined(CPU_STAT)
    cpu_start = clock();
#endif

    while (!done) {
      _ArrayCopy1D_(index,index1,ndims);
      _ArrayCopy1D_(index,index2,ndims); index2[d]++;
      _ArrayIndex1D_(ndims,dim          ,index ,ghosts,p);
      _ArrayIndex1D_(ndims,dim_interface,index1,0     ,p1);
      _ArrayIndex1D_(ndims,dim_interface,index2,0     ,p2);
      for (v=0; v<nvars; v++) hyp[nvars*p+v] += dxinv[offset+ghosts+index[d]]
                                              * (FluxI[nvars*p2+v]-FluxI[nvars*p1+v]);
      /* boundary flux integral */
      if (index[d] == 0)
        for (v=0; v<nvars; v++) solver->StageBoundaryIntegral[(2*d+0)*nvars+v] -= FluxI[nvars*p1+v];
      if (index[d] == dim[d]-1)
        for (v=0; v<nvars; v++) solver->StageBoundaryIntegral[(2*d+1)*nvars+v] += FluxI[nvars*p2+v];

      _ArrayIncrementIndex_(ndims,dim,index,done);
    }

#if defined(CPU_STAT)
    cpu_end = clock();
    cpu_time += (double)(cpu_end - cpu_start) / CLOCKS_PER_SEC;
#endif

    offset += dim[d] + 2*ghosts;
  }

#if defined(CPU_STAT)
  printf("HyperbolicFunction CPU time = %8.6lf\n", cpu_time);
#endif

  if (solver->flag_ib) _ArrayBlockMultiply_(hyp,solver->iblank,size,nvars);

  return(0);
}

int ReconstructHyperbolic(
                            double  *fluxI,     
                            double  *fluxC,     
                            double  *u,         
                            double  *x,         
                            int     dir,        
                            void    *s,         
                            void    *m,         
                            double  t,          
                            int     LimFlag,    
                            int(*UpwindFunction)(double*,double*,double*,double*,double*,double*,int,void*,double)
                          )
{
  HyPar         *solver = (HyPar*)        s;
  MPIVariables  *mpi    = (MPIVariables*) m;
  _DECLARE_IERR_;

  double *uC     = NULL;
  double *uL     = solver->uL;
  double *uR     = solver->uR;
  double *fluxL  = solver->fL;
  double *fluxR  = solver->fR;

  /*
    precalculate the non-linear interpolation coefficients if required
    else reuse the weights previously calculated
  */

  if (LimFlag) IERR solver->SetInterpLimiterVar(fluxC,u,x,dir,solver,mpi);

  /* if defined, calculate the modified u-function to be used for upwinding
     e.g.: used in well-balanced schemes for Euler/Navier-Stokes with gravity
     otherwise, just copy u to uC */
  if (solver->UFunction) {
    uC = solver->uC;
    IERR solver->UFunction(uC,u,dir,solver,mpi,t); CHECKERR(ierr);
  } else uC = u;

  /* Interpolation -> to calculate left and right-biased interface flux and state variable*/
  IERR solver->InterpolateInterfacesHyp(uL   ,uC   ,u,x, 1,dir,solver,mpi,1); CHECKERR(ierr);
  IERR solver->InterpolateInterfacesHyp(uR   ,uC   ,u,x,-1,dir,solver,mpi,1); CHECKERR(ierr);
  IERR solver->InterpolateInterfacesHyp(fluxL,fluxC,u,x, 1,dir,solver,mpi,0); CHECKERR(ierr);
  IERR solver->InterpolateInterfacesHyp(fluxR,fluxC,u,x,-1,dir,solver,mpi,0); CHECKERR(ierr);

  /* Upwind -> to calculate the final interface flux */
  if (UpwindFunction) { IERR UpwindFunction   (fluxI,fluxL,fluxR,uL  ,uR  ,u   ,dir,solver,t); CHECKERR(ierr); }
  else                { IERR DefaultUpwinding (fluxI,fluxL,fluxR,NULL,NULL,NULL,dir,solver,t); CHECKERR(ierr); }

  return(0);
}

int DefaultUpwinding(
                      double  *fI,  
                      double  *fL,  
                      double  *fR,  
                      double  *uL,  
                      double  *uR,  
                      double  *u,   
                      int     dir,  
                      void    *s,   
                      double  t     
                    )
{
  HyPar *solver = (HyPar*)    s;
  int   done;

  int *dim  = solver->dim_local;
  int ndims = solver->ndims;
  int nvars = solver->nvars;

  int bounds_outer[ndims], bounds_inter[ndims];
  _ArrayCopy1D_(dim,bounds_outer,ndims); bounds_outer[dir] =  1;
  _ArrayCopy1D_(dim,bounds_inter,ndims); bounds_inter[dir] += 1;

  done = 0; int index_outer[ndims], index_inter[ndims];
  _ArraySetValue_(index_outer,ndims,0);
  while (!done) {
    _ArrayCopy1D_(index_outer,index_inter,ndims);
    for (index_inter[dir] = 0; index_inter[dir] < bounds_inter[dir]; index_inter[dir]++) {
      int p; _ArrayIndex1D_(ndims,bounds_inter,index_inter,0,p);
      int v; for (v=0; v<nvars; v++) fI[nvars*p+v] = 0.5 * (fL[nvars*p+v]+fR[nvars*p+v]);
    }
    _ArrayIncrementIndex_(ndims,bounds_outer,index_outer,done);
  }

  return(0);
}