void doCollision(double *collideField, int *flagField, const double * const tau,int xlength){
double density;
double velocity[3];
double feq[Q];
double* currentCell;
int currentIndex;
/* Set pointer to first cell that is not a boundary */
currentIndex = (xlength+3);
/* Last row is a border */
while(currentIndex < (xlength+2)*(xlength+2)*(xlength+2) - (xlength+2))
{
/* No left and right border, only inner cells */
if(flagField[currentIndex] == FLUID)
{
currentCell = &collideField[currentIndex*Q];
computeDensity(currentCell, &density);
computeVelocity(currentCell, &density, velocity);
computeFeq(&density, velocity, feq);
computePostCollisionDistributions(currentCell, tau, feq);
}
currentIndex++;
}
}
void doCollision(double *collideField, int *flagField, const double * const tau, int * length){
/*
* For each inner grid cell in collideField, compute the post-collide
* distribution
*/
double density;
double velocity[D];
double feq[Q];
double * currentCell;
int x,y,z;
int node[3];
int n[3] = { length[0] + 2, length[1] + 2, length[2] + 2 };
// Loop over inner cells: compare to streaming.c
for (z = 1; z <= length[2]; z++) {
node[2] = z;
for (y = 1; y <= length[1]; y++) {
node[1] = y;
for (x = 1; x <= length[0]; x++) {
node[0] = x;
currentCell = getEl(collideField, node, 0, n);
computeDensity(currentCell, &density);
computeVelocity(currentCell, &density, velocity);
computeFeq(&density, velocity, feq);
computePostCollisionDistributions(currentCell, tau, feq);
}
}
}
}
void doCollision(double *collideField, int *flagField, const double * const tau,
const int * const sublength)
{
for (int z = 1; z < sublength[0] + 1; ++z) {
for (int y = 1; y < sublength[1] + 1; ++y) {
for (int x = 1; x < sublength[2] + 1; ++x) {
double *currentCell = &collideField[idx(sublength, x, y, z, 0)];
/*Updating values for velocity, density and Feq for Current cell*/
double density;
computeDensity(currentCell, &density);
double velocity[D];
computeVelocity(currentCell, &density, velocity);
double feq[Q];
computeFeq(&density, velocity, feq);
computePostCollisionDistributions(currentCell, tau, feq);
}
}
}
}
void doCollision(double *collideField, int *flagField,const double * const tau,int xlength)
{
double velocity[3], density, feq[PARAMQ], *currentCell;
for (int z = 1; z <= xlength; z++)
for (int y = 1; y <= xlength ; y++)
for (int x = 1; x <= xlength; x++)
{
currentCell = collideField + PARAMQ * (z * (xlength + 2) * (xlength + 2) + y * (xlength + 2) + x);
density = 0.0;
computeDensitySSE(currentCell, &density);
if (__builtin_expect(fabs(1.0 - density) > 0.1, 0))
fprintf(stderr, "WARNING: Density is %.3f in cell (%d, %d, %d)\n", density, x, y, z);
computeVelocitySSE(currentCell, &density, velocity);
computeFeq(&density, velocity, feq);
computePostCollisionDistributions(currentCell, tau, feq);
}
}
void doCollision(double *collideField, int *flagField,const double * const tau, int *subdomain){
double density;
double velocity[D];
double feq[Q];
double *currentCell = NULL; // currentCell points to the first distribution function within the respective cell
for (int iz=1; iz<=subdomain[2]; iz++){
for (int iy=1; iy<=subdomain[1]; iy++){
for (int ix=1; ix<=subdomain[0]; ix++){
// set pointer to current cell
currentCell = collideField + Q * compute_index(ix, iy, iz, subdomain);
// compute density, velocity and equilibrium prob. distrib. for this cell
computeDensity ( currentCell, &density );
computeVelocity ( currentCell, &density, velocity );
computeFeq ( &density, velocity, feq );
computePostCollisionDistributions ( currentCell, tau, feq );
}
}
}
}
/** carries out the whole local collision process. Computes density and velocity and
* equilibrium distributions. Carries out BGK update.
*/
void doCollision(double *collideField, int *flagField,const double * const tau,int xlength){
int x,y,z ;
int counter;
double density;
double velocity[3] ;
double feq[Q] ;
/* we loop over all the inner cells i.e. fluid cells */
for (z = 1; z < xlength+1; z++) {
for (y = 1; y < xlength+1; y++) {
for (x = 1; x < xlength+1; x++) {
/* get the current index */
counter = Q*(z*(xlength+2)*(xlength+2) + y * (xlength+2) + x );
/* Compute density, velocity, f_eq to finally get the postcollision distribution */
computeDensity (&collideField[counter], &density) ;
computeVelocity(&collideField[counter], &density,velocity) ;
computeFeq(&density,velocity,feq) ;
computePostCollisionDistributions(&collideField[counter],tau,feq);
}
}
}
}
