BurgersInitialize.c File Reference

Initialize the Burgers module. More...

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <basic.h>
#include <arrayfunctions.h>
#include <bandedmatrix.h>
#include <physicalmodels/burgers.h>
#include <mpivars.h>
#include <hypar.h>

Go to the source code of this file.

Functions
double	BurgersComputeCFL (void *, void *, double, double)
int	BurgersAdvection (double *, double *, int, void *, double)
int	BurgersUpwind (double *, double *, double *, double *, double *, double *, int, void *, double)
int	BurgersInitialize (void *s, void *m)

Detailed Description

Initialize the Burgers module.

Author

John Loffeld

Definition in file BurgersInitialize.c.

Function Documentation

BurgersComputeCFL()

double BurgersComputeCFL	(	void *	s,
		void *	m,
		double	dt,
		double	t
	)

Computes the maximum CFL number over the domain. Note that the CFL is computed over the local domain on this processor only.

Parameters

s	Solver object of type HyPar
m	MPI object of type MPIVariables
dt	Time step size for which to compute the CFL
t	Time

Definition at line 15 of file BurgersComputeCFL.c.

{
  HyPar    *solver = (HyPar*)   s;
  Burgers  *params = (Burgers*) solver->physics;

  int     ndims  = solver->ndims;
  int     nvars  = solver->nvars;
  int     ghosts = solver->ghosts;
  int     *dim   = solver->dim_local;
  double  *u     = solver->u;

  int index[ndims], dir, v;

  double  max_cfl = 0;
  int done = 0; _ArraySetValue_(index,ndims,0);
  while (!done) {
    int p; _ArrayIndex1D_(ndims,dim,index,ghosts,p);
    for (v=0; v<nvars; v++) {
      for (dir=0; dir<ndims; dir++) {
        double dxinv;
        _GetCoordinate_(dir,index[dir],dim,ghosts,solver->dxinv,dxinv); /* 1/dx */
        double local_cfl = u[nvars*p+v]*dt*dxinv; 
        if (local_cfl > max_cfl) max_cfl = local_cfl;
      }
    }
    _ArrayIncrementIndex_(ndims,dim,index,done);
  }

  return(max_cfl);
}

BurgersAdvection()

int BurgersAdvection	(	double *	f,
		double *	u,
		int	dir,
		void *	s,
		double	t
	)

Compute the hyperbolic flux over the local domain.

\begin{equation} {\bf F}\left({\bf u}\right) = 0.5 {\bf u}^2 \end{equation}

Parameters

f	Array to hold the computed flux (same size and layout as u)
u	Array containing the conserved solution
dir	Spatial dimension
s	Solver object of type HyPar
t	Current time

Definition at line 17 of file BurgersAdvection.c.

{
  HyPar     *solver = (HyPar*)   s;
  Burgers   *param  = (Burgers*) solver->physics;
  int        i, v;

  int *dim    = solver->dim_local;
  int ghosts  = solver->ghosts;
  int ndims   = solver->ndims;
  int nvars   = solver->nvars;
  int index[ndims], bounds[ndims], offset[ndims];

  /* set bounds for array index to include ghost points */
  _ArrayCopy1D_(dim,bounds,ndims);
  for (i=0; i<ndims; i++) bounds[i] += 2*ghosts;

  /* set offset such that index is compatible with ghost point arrangement */
  _ArraySetValue_(offset,ndims,-ghosts);

  int done = 0; _ArraySetValue_(index,ndims,0);
  while (!done) {
    int p; _ArrayIndex1DWO_(ndims,dim,index,offset,ghosts,p);
    for (v = 0; v < nvars; v++) f[nvars*p+v] = 0.5 * u[nvars*p+v] * u[nvars*p+v];
    _ArrayIncrementIndex_(ndims,bounds,index,done);
  }

  return(0);
}

BurgersUpwind()

int BurgersUpwind	(	double *	fI,
		double *	fL,
		double *	fR,
		double *	uL,
		double *	uR,
		double *	u,
		int	dir,
		void *	s,
		double	t
	)

Upwinding scheme for the Burgers equations

Parameters

fI	Computed upwind interface flux
fL	Left-biased reconstructed interface flux
fR	Right-biased reconstructed interface flux
uL	Left-biased reconstructed interface solution
uR	Right-biased reconstructed interface solution
u	Cell-centered solution
dir	Spatial dimension
s	Solver object of type HyPar
t	Current solution time

Definition at line 15 of file BurgersUpwind.c.

{
  HyPar   *solver = (HyPar*)   s;
  Burgers *param  = (Burgers*) solver->physics;
  int     done,v;

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

  int index_outer[ndims], index_inter[ndims], 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; _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 indexL[ndims]; _ArrayCopy1D_(index_inter,indexL,ndims); indexL[dir]--;
      int indexR[ndims]; _ArrayCopy1D_(index_inter,indexR,ndims);
      int pL; _ArrayIndex1D_(ndims,dim,indexL,ghosts,pL);
      int pR; _ArrayIndex1D_(ndims,dim,indexR,ghosts,pR);

      for (v = 0; v < nvars; v++) {
        double eigL = u[nvars*pL+v],
               eigR = u[nvars*pR+v];

        if ((eigL > 0) && (eigR > 0)) {
           fI[nvars*p+v] = fL[nvars*p+v];
        } else if ((eigL < 0) && (eigR < 0)) {
           fI[nvars*p+v] = fR[nvars*p+v];
        } else { 
           double alpha = max(absolute(eigL), absolute(eigR));
           fI[nvars*p+v] = 0.5 * (fL[nvars*p+v] + fR[nvars*p+v] - alpha * (uR[nvars*p+v] - uL[nvars*p+v]));
        }
      }

    }
    _ArrayIncrementIndex_(ndims,bounds_outer,index_outer,done);

  }

  return(0);
}

BurgersInitialize()

int BurgersInitialize	(	void *	s,
		void *	m
	)

Initialize the nonlinear Burgers physics module - allocate and set physics-related parameters, read physics-related inputs from file, and set the physics-related function pointers in HyPar

Parameters

s	Solver object of type HyPar
m	Object of type MPIVariables containing MPI-related info

Definition at line 25 of file BurgersInitialize.c.

{
  HyPar         *solver  = (HyPar*)        s;
  MPIVariables  *mpi     = (MPIVariables*) m; 
  Burgers       *physics = (Burgers*)      solver->physics;
  int           i, ferr;

  static int count = 0;

  /* reading physical model specific inputs - all processes */
  if (!mpi->rank) {
    FILE *in;
    in = fopen("physics.inp","r");
    if (in) {
      if (!count) printf("Reading physical model inputs from file \"physics.inp\".\n");
      char word[_MAX_STRING_SIZE_];
      ferr = fscanf(in,"%s",word); if (ferr != 1) return(1);
      if (!strcmp(word, "begin")){
          while (strcmp(word, "end")){
              ferr = fscanf(in,"%s",word); if (ferr != 1) return(1);
          if (strcmp(word,"end")) {
            char useless[_MAX_STRING_SIZE_];
            ferr = fscanf(in,"%s",useless); if (ferr != 1) return(ferr);
            printf("Warning: keyword %s in file \"physics.inp\" with value %s not ",
                    word, useless);
            printf("recognized or extraneous. Ignoring.\n");
          }
        }
        } else {
          fprintf(stderr,"Error: Illegal format in file \"physics.inp\".\n");
        return(1);
        }
    }
    fclose(in);
  }

  if (!strcmp(solver->SplitHyperbolicFlux,"yes")) {
    if (!mpi->rank) {
      fprintf(stderr,"Error in BurgersInitialize: This physical model does not have a splitting ");
      fprintf(stderr,"of the hyperbolic term defined.\n");
    }
    return(1);
  }

#ifndef serial
#endif

  /* initializing physical model-specific functions */
  solver->ComputeCFL = BurgersComputeCFL;
  solver->FFunction  = BurgersAdvection;
  solver->Upwind     = BurgersUpwind;

  count++;
  return(0);
}