Euler1DSourceUpwind.c File Reference

Contains functions to compute the "upwind" source term at an interface (for a balanced finite-difference discretization of the 1D Euler equations with gravitational source terms). More...

#include <stdlib.h>
#include <math.h>
#include <basic.h>
#include <arrayfunctions.h>
#include <mathfunctions.h>
#include <physicalmodels/euler1d.h>
#include <hypar.h>

Go to the source code of this file.

Functions
int	Euler1DSourceUpwindLLF (double *fI, double *fL, double *fR, double *u, int dir, void *s, double t)
int	Euler1DSourceUpwindRoe (double *fI, double *fL, double *fR, double *u, int dir, void *s, double t)

Detailed Description

Contains functions to compute the "upwind" source term at an interface (for a balanced finite-difference discretization of the 1D Euler equations with gravitational source terms).

Author

Debojyoti Ghosh

Definition in file Euler1DSourceUpwind.c.

Function Documentation

Euler1DSourceUpwindLLF()

int Euler1DSourceUpwindLLF	(	double *	fI,
		double *	fL,
		double *	fR,
		double *	u,
		int	dir,
		void *	s,
		double	t
	)

Compute the "upwind" source term in the balanced formulation introduced in the reference below. The "upwind" state is just the arithmetic average of the left and right states.

• Xing, Shu, "High Order Well-Balanced WENO Scheme for the Gas Dynamics Equations Under Gravitational Fields", J. Sci. Comput., 54, 2013, pp. 645–662, http://dx.doi.org/10.1007/s10915-012-9585-8.

Parameters

fI	Computed interface source term ("upwinded")
fL	Left-biased interface source term
fR	Right-biased interface source term
u	Solution (conserved variables)
dir	Spatial dimension (unused since this is a 1D case)
s	Solver object of type HyPar
t	Current solution time

Definition at line 21 of file Euler1DSourceUpwind.c.

{
  HyPar     *solver = (HyPar*)    s;
  int       done,k;
  _DECLARE_IERR_;

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

  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);
      /* Local Lax-Friedrich upwinding scheme */
      for (k = 0; k < _MODEL_NVARS_; k++) 
        (fI+_MODEL_NVARS_*p)[k] = 0.5 * ((fL+_MODEL_NVARS_*p)[k] + (fR+_MODEL_NVARS_*p)[k]);
    }
    _ArrayIncrementIndex_(ndims,bounds_outer,index_outer,done);
  }

  return(0);
}

Euler1DSourceUpwindRoe()

int Euler1DSourceUpwindRoe	(	double *	fI,
		double *	fL,
		double *	fR,
		double *	u,
		int	dir,
		void *	s,
		double	t
	)

Compute the "upwind" source term in the balanced formulation introduced in the reference below. The "upwind" state is just the arithmetic average of the left and right states.

• Xing, Shu, "High Order Well-Balanced WENO Scheme for the Gas Dynamics Equations Under Gravitational Fields", J. Sci. Comput., 54, 2013, pp. 645–662, http://dx.doi.org/10.1007/s10915-012-9585-8.

Parameters

fI	Computed interface source term ("upwinded")
fL	Left-biased interface source term
fR	Right-biased interface source term
u	Solution (conserved variables)
dir	Spatial dimension (unused since this is a 1D case)
s	Solver object of type HyPar
t	Current solution time

Definition at line 64 of file Euler1DSourceUpwind.c.

{
  HyPar     *solver = (HyPar*)    s;
  int       done,k;
  _DECLARE_IERR_;

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

  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);
      /* Local Lax-Friedrich upwinding scheme */
      for (k = 0; k < _MODEL_NVARS_; k++) 
        (fI+_MODEL_NVARS_*p)[k] = 0.5 * ((fL+_MODEL_NVARS_*p)[k] + (fR+_MODEL_NVARS_*p)[k]);
    }
    _ArrayIncrementIndex_(ndims,bounds_outer,index_outer,done);
  }

  return(0);
}