M1 RK1 and FLD

Movies

8 movies available from 8 completed runs. Open the movie gallery.

Saved states are shown with zero-order hold and no solution interpolation.

Gaussian Pulse · L0 · M1 RK1Gaussian Pulse · L0 · FLD backward EulerMarshak · L0 · M1 RK1Marshak · L0 · FLD backward EulerGaussian Pulse · L1 · M1 RK1Gaussian Pulse · L1 · FLD backward EulerMarshak · L1 · M1 RK1Marshak · L1 · FLD backward Euler

Status: completed. Initial stationary comparison; model discrepancies are not FLD error estimates. FLD uses a serial root-gathered multigrid solve. No moving-gas or scaling claim.

M1 evolves radiation energy and flux using RK1 with radiation substeps. FLD solves energy and material heating together implicitly; its flux is a derived diagnostic. Cross-model differences are not truncation-error estimates.

Model comparison plots

Time is in seconds for the scaled Gaussian problem and normalized units for Marshak. FLD includes periodic Gaussian and Su–Olson analytic diffusion-limit references for energy and flux, plus Marshak material energy. These references are not exact nonlinear LP FLD solutions. Reference discrepancies remain separate from cross-model differences. The initial plan is a short implementation comparison, not a full-duration production qualification.

Supported scope

Gaussian pulse and stationary Marshak heating support both models, with physical light speed on CPU.

• streaming_wave: M1 RK1 only; unsupported by stationary FLD.
• streaming_front: M1 RK1 only; unsupported by stationary FLD.
• equilibrium_sphere: M1 RK1 only; unsupported by stationary FLD.
• subcritical_shock: M1 RK1 only; unsupported by stationary FLD.
• supercritical_shock: M1 RK1 only; unsupported by stationary FLD.
• radiating_blast: M1 RK1 only; unsupported by stationary FLD.

Plan and provenance · Prepared commands

Execution requires a separate explicit start. This workflow does not publish to a remote website.