/** Calculate temperature of the LB fluid.
* \param result Fluid temperature
*/
void lb_calc_fluid_temp(double *result) {
int x, y, z, index;
double local_rho, local_j2;
double temp = 0.0;
for (x=1; x<=lblattice.grid[0]; x++) {
for (y=1; y<=lblattice.grid[1]; y++) {
for (z=1; z<=lblattice.grid[2]; z++) {
index = get_linear_index(x,y,z,lblattice.halo_grid);
lb_calc_local_j(&lbfluid[index]);
lb_calc_local_rho(&lbfluid[index]);
local_rho = *lbfluid[index].rho;
local_j2 = scalar(lbfluid[index].j,lbfluid[index].j);
temp += local_j2;
}
}
}
temp *= 1./(lbpar.rho*lblattice.grid_volume*lbpar.tau*lbpar.tau*pow(lblattice.agrid,4));
MPI_Reduce(&temp, result, 1, MPI_DOUBLE, MPI_SUM, 0, MPI_COMM_WORLD);
}
/** Calculate momentum of the LB fluid.
* \param result Fluid momentum
*/
void lb_calc_fluid_momentum(double *result) {
int x, y, z, index;
double j[3], momentum[3] = { 0.0, 0.0, 0.0 };
for (x=1; x<=lblattice.grid[0]; x++) {
for (y=1; y<=lblattice.grid[1]; y++) {
for (z=1; z<=lblattice.grid[2]; z++) {
index = get_linear_index(x,y,z,lblattice.halo_grid);
lb_calc_local_j(index,j);
momentum[0] += j[0] + lbfields[index].force[0];
momentum[1] += j[1] + lbfields[index].force[1];
momentum[2] += j[2] + lbfields[index].force[2];
}
}
}
momentum[0] *= lblattice.agrid/lbpar.tau;
momentum[1] *= lblattice.agrid/lbpar.tau;
momentum[2] *= lblattice.agrid/lbpar.tau;
MPI_Reduce(momentum, result, 3, MPI_DOUBLE, MPI_SUM, 0, MPI_COMM_WORLD);
}
/** Calculate a velocity profile for the LB fluid. */
void lb_calc_velocity_profile(double *velprof, int vcomp, int pdir, int x1, int x2) {
int index, dir[3];
double local_rho, local_j;
/* \todo generalize and parallelize */
dir[(pdir+1)%3] = x1;
dir[(pdir+2)%3] = x2;
for (dir[pdir]=1;dir[pdir]<=lblattice.grid[pdir];dir[pdir]++) {
index = get_linear_index(dir[0],dir[1],dir[2],lblattice.halo_grid);
lb_calc_local_j(&lbfluid[index]);
lb_calc_local_rho(&lbfluid[index]);
local_rho = *lbfluid[index].rho;
local_j = lbfluid[index].j[vcomp];
if (local_j == 0) {
velprof[dir[pdir]-1] = 0.0;
} else {
velprof[dir[pdir]-1] = local_j/local_rho * lblattice.agrid/lbpar.tau;
}
}
}
