LinearADRAdvection.c File Reference

Function to evaluate the advection term in the linear advection-diffusion-reaction model. More...

#include <stdlib.h>
#include <basic.h>
#include <arrayfunctions.h>
#include <physicalmodels/linearadr.h>
#include <hypar.h>

Go to the source code of this file.

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

Detailed Description

Function to evaluate the advection term in the linear advection-diffusion-reaction model.

Author

Debojyoti Ghosh

Definition in file LinearADRAdvection.c.

Function Documentation

LinearADRAdvection()

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

Evaluate the advection term in the linear advection-diffusion-reaction model:
Compute

\begin{equation} a_d u \end{equation}

given \(u\) and \(d\) in the hyperbolic term

\begin{equation} \sum_d \frac {\partial} {\partial x_d} \left( a_d u \right) \end{equation}

• If the advection field is spatially varying, then the advection speed array (LinearADR::a) is expected to have the size (LinearADR::adv_arr_size): (number of grid points with ghosts - HyPar::npoints_local_wghosts) X (number of spatial dimensions - HyPar::ndims) X (number of solution components - HyPar::nvars), with the innermost loop being the solution components and outermost loop being the grid points.
• If the advection field is constant, then the advection speed array (LinearADR::a) is expected to have the size (LinearADR::adv_arr_size): (number of spatial dimensions - HyPar::ndims) X (number of solution components - HyPar::nvars), with the inner loop being the solution components.

Parameters

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

Definition at line 37 of file LinearADRAdvection.c.

{
  HyPar     *solver = (HyPar*)     s;
  LinearADR *param  = (LinearADR*) solver->physics;
  double    *adv    = param->a;
  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);
  if (param->constant_advection == 1) {
    while (!done) {
      int p; _ArrayIndex1DWO_(ndims,dim,index,offset,ghosts,p);
      for (v = 0; v < nvars; v++) {
        f[nvars*p+v] = param->a[nvars*dir+v] * u[nvars*p+v];
      }
      _ArrayIncrementIndex_(ndims,bounds,index,done);
    }
  } else if (param->constant_advection == 0) {
    while (!done) {
      int p; _ArrayIndex1DWO_(ndims,dim,index,offset,ghosts,p);
      for (v = 0; v < nvars; v++) {
        double a = adv[nvars*ndims*p+nvars*dir+v];
        f[nvars*p+v] = a * u[nvars*p+v];
      }
      _ArrayIncrementIndex_(ndims,bounds,index,done);
    }
  } else {
    while (!done) {
      int p; _ArrayIndex1DWO_(ndims,dim,index,offset,ghosts,p);
      for (v = 0; v < nvars; v++) {
        f[nvars*p+v] = 0.0;
      }
      _ArrayIncrementIndex_(ndims,bounds,index,done);
    }
  }

  return(0);
}