Combining Cell- and Point-Centered Methods in 3D, Unstructured-Grid Radiation–Hydrodynamic Codes

We describe the coupling of a cell-centered hydrodynamic scheme to a point-centered finite element method simulating diffusive processes such as heat conduction and radiation transport. We also discuss procedures that compute the material coefficients, the scheme advancing the radiation energy, and how to tally diffusion boundary fluxes in sections with Dirichlet boundary data. To demonstrate the couplingʹs robustness and accuracy, we simulate the implosion of a radiatively driven inertial confinement fusion capsule. The simulation, done on an unstructured, 3D, tetrahedral grid, maintains spherical symmetry.