TimeRHSFunctionExplicit.c File Reference

Right-hand-side computation for explicit time integration. More...

#include <basic.h>
#include <arrayfunctions_gpu.h>
#include <mpivars.h>
#include <hypar.h>
#include <time.h>

Go to the source code of this file.

Functions
int	TimeRHSFunctionExplicit (double *rhs, double *u, void *s, void *m, double t)

Detailed Description

Right-hand-side computation for explicit time integration.

Author

Debojyoti Ghosh, Youngdae Kim

Definition in file TimeRHSFunctionExplicit.c.

Function Documentation

TimeRHSFunctionExplicit()

int TimeRHSFunctionExplicit	(	double *	rhs,
		double *	u,
		void *	s,
		void *	m,
		double	t
	)

This function computes the right-hand-side of the ODE given by

\begin{equation} \frac {{\bf u}}{dt} = {\bf F}\left({\bf u}\right) \end{equation}

for explicit time integration methods, i.e., where

\begin{equation} {\bf F}\left({\bf u}\right) = - {\bf F}_{\rm hyperbolic}\left({\bf u}\right) + {\bf F}_{\rm parabolic} \left({\bf u}\right) + {\bf F}_{\rm source} \left({\bf u}\right), \end{equation}

given the solution \({\bf u}\) and the current simulation time.

Parameters

rhs	Array to hold the computed right-hand-side
u	Array holding the solution
s	Solver object of type HyPar
m	MPI object of type MPIVariables
t	Current simulation time

Definition at line 30 of file TimeRHSFunctionExplicit.c.

{
  HyPar           *solver = (HyPar*)        s;
  MPIVariables    *mpi    = (MPIVariables*) m;
  int             d;

  int size = 1;
  for (d=0; d<solver->ndims; d++) size *= (solver->dim_local[d]+2*solver->ghosts);

  /* apply boundary conditions and exchange data over MPI interfaces */
  solver->ApplyBoundaryConditions(solver,mpi,u,NULL,t);
  solver->ApplyIBConditions(solver,mpi,u,t);

  /* Evaluate hyperbolic, parabolic and source terms  and the RHS */
#if defined(HAVE_CUDA)
  if (solver->use_gpu) {
    gpuMPIExchangeBoundariesnD( solver->ndims,
                                solver->nvars,
                                solver->gpu_dim_local,
                                solver->ghosts,
                                mpi,
                                u );
  } else {
#endif
    MPIExchangeBoundariesnD(  solver->ndims,
                              solver->nvars,
                              solver->dim_local,
                              solver->ghosts,
                              mpi,
                              u);
#if defined(HAVE_CUDA)
  }
#endif

    solver->HyperbolicFunction( solver->hyp,
                                u,
                                solver,
                                mpi,
                                t,
                                1,
                                solver->FFunction,
                                solver->Upwind );
    solver->ParabolicFunction(solver->par,u,solver,mpi,t);
    solver->SourceFunction(solver->source,u,solver,mpi,t);

#if defined(HAVE_CUDA)
  if (solver->use_gpu) {
    gpuArraySetValue(rhs, size*solver->nvars, 0.0);
    gpuArrayAXPY(solver->hyp,    -1.0, rhs, size*solver->nvars);
    gpuArrayAXPY(solver->par,     1.0, rhs, size*solver->nvars);
    gpuArrayAXPY(solver->source,  1.0, rhs, size*solver->nvars);
  } else {
#endif
    _ArraySetValue_(rhs,size*solver->nvars,0.0);
    _ArrayAXPY_(solver->hyp   ,-1.0,rhs,size*solver->nvars);
    _ArrayAXPY_(solver->par   , 1.0,rhs,size*solver->nvars);
    _ArrayAXPY_(solver->source, 1.0,rhs,size*solver->nvars);
#if defined(HAVE_CUDA)
  }
#endif

  return(0);
}