Crash: A Block-Adaptive-Mesh Code for Radiative Shock Hydrodynamics—implementation and Verification

Abstract

We describe the CRASH (Center for Radiative Shock Hydrodynamics) code, a block adaptive mesh code for multi-material radiation hydrodynamics. The implementation solves the radiation diffusion model with the gray or multigroup method and uses a flux limited diffusion approximation to recover the free-streaming limit. The electrons and ions are allowed to have different temperatures and we include a flux limited electron heat conduction. The radiation hydrodynamic equations are solved in the Eulerian frame by means of a conservative finite volume discretization in either one, two, or three-dimensional slab geometry or in two-dimensional cylindrical symmetry. An operator split method is used to solve these equations in three substeps:(1) solve the hydrodynamic equations with shock-capturing schemes, (2) a linear advection of the radiation in frequency-logarithm space, and (3) an implicit solve of the stiff radiation diffusion, heat conduction, and energy exchange. We present a suite of verification test problems to demonstrate the accuracy and performance of the algorithms. The CRASH code is an extension of the Block-Adaptive Tree Solarwind Roe Upwind Scheme (BATS-R-US) code with this new radiation transfer and heat conduction library and equation-of-state and multigroup opacity solvers. Both CRASH and BATS-R-US are part of the publicly available Space Weather Modeling Framework (SWMF).

Observation of Single-Mode, Kelvin-Helmholtz Instability in a Supersonic Flow

“…We drove the experiment using three sequential laser beams, each HYADES is a Lagrangian radiation-hydrodynamic code including a laser-absorption model. Additional 2D modeling with CRASH [24], which has a multi-dimensional laser package, also confirm the modeling of the laserdriven behavior. The experiment was designed so that the vorticity produced by baroclinic effects was small compared to that driven by the steady, shear flow.…”

Multiphysics simulations: challenges and opportunities.

“…Lagrangian, Eulerian, and hybrid approaches (e.g., arbitrary Lagrangian-Eulerian [ALE] methods) are used. Such techniques also translate to solution of the radiation (Bowers and Wilson, 1982;Bruenn, 1985;Myra et al, 1987;Turner and Stone, 2001;Swesty and Myra, 2009;van der Holst et al, 2011). Here, however, : Interacting shock waves propagating in a simulation of a high-energy-density physics shock-tube experiment .…”

Investigating applications portability with the Uintah DAG-based runtime system on PetaScale supercomputers

“…These results are significant in that other adaptive mesh codes using similar approaches in radiative shock hydrodynamics, astrophysics and cosmology, e.g. Crash and Enzo [64,65] report scaling to a maximum of near 1000 cores. The hybrid memory approach used by Uintah has also contributed to our results, as only one copy of the geometry is needed per multi-core node.…”