geom::FieldCell<Scal> CalcRadiationField(
const Mesh& mesh,
const geom::MapFace<std::shared_ptr<solver::ConditionFace>>&
mf_cond_radiation_shared,
const geom::FieldCell<Scal>& fc_absorption_rate,
Vect radiation_direction,
geom::FieldCell<Scal> initial_guess) {
if (radiation_direction.norm() == 0.) {
return initial_guess;
}
radiation_direction /= radiation_direction.norm();
geom::FieldFace<Scal> ff_flux(mesh);
for (auto idxface : mesh.Faces()) {
ff_flux[idxface] =
radiation_direction.dot(mesh.GetSurface(idxface));
}
Scal time_step = 1e16;
for (auto idxcell : mesh.Cells()) {
for (size_t i = 0; i < mesh.GetNumNeighbourFaces(idxcell); ++i) {
auto idxface = mesh.GetNeighbourFace(idxcell, i);
Vect vect = mesh.GetCenter(idxcell) - mesh.GetCenter(idxface);
Scal vel_dot_vect = std::abs(radiation_direction.dot(vect));
if (vel_dot_vect != 0.) {
time_step = std::min(time_step, vect.sqrnorm() / vel_dot_vect);
}
}
}
geom::FieldCell<Scal> fc_source(mesh, 0.);
solver::AdvectionSolverExplicit<Mesh, geom::FieldFace<Scal>>
advection(
mesh, initial_guess, mf_cond_radiation_shared, &ff_flux,
&fc_source, 0., time_step);
Scal error = 1e16;
size_t count = 0;
for (; count < 10 && error > 1e-3; ++count) {
for (auto idxcell : mesh.Cells()) {
fc_source[idxcell] =
-fc_absorption_rate[idxcell] * advection.GetField()[idxcell];
}
advection.StartStep();
advection.MakeIteration();
error = advection.GetConvergenceIndicator();
advection.FinishStep();
}
return advection.GetField();
}
