Function opensn::ApplyDSACorrectionToDelayedAngularFlux

Function Documentation

void opensn::ApplyDSACorrectionToDelayedAngularFlux(DiscreteOrdinatesProblem &do_problem, const LBSGroupset &groupset, const std::vector<double> &delta_phi_local)

Applies a diffusion-synthetic scalar-flux correction to the lagged (delayed) incoming angular fluxes of a groupset, as the isotropic angular correction delta psi = delta phi (quadrature weights sum to one).

Lagged fluxes are those of opposing reflecting boundaries and those where the sweep broke a cyclic dependency, within a location or between locations. Each is corrected with delta phi at the face node of the downwind cell that reads it.

The iteration carries the lagged angular fluxes as unknowns alongside phi. An acceleration update that corrects phi but not these fluxes leaves their error to re-enter on the next sweep, which can make source iteration with DSA diverge.

delta_phi_local has the layout of the local flux-moment vector.