Multi-Material ALE with AMR for Modeling Hot Plasmas and Cold Fragmenting Materials

Abstract

We have developed a new 3D multi-physics multi-material code, ALE-AMR, which combines Arbitrary Lagrangian Eulerian (ALE) hydrodynamics with Adaptive Mesh Refinement (AMR) to connect the continuum to the microstructural regimes. The code is unique in its ability to model hot radiating plasmas and cold fragmenting solids. New numerical techniques were developed for many of the physics packages to work efficiently on a dynamically moving and adapting mesh. We use interface reconstruction based on volume fractions of the material components within mixed zones and reconstruct interfaces as needed. This interface reconstruction model is also used for void coalescence and fragmentation. A flexible strength/failure framework allows for pluggable material models, which may require material history arrays to determine the level of accumulated damage or the evolving yield stress in J2 plasticity models. For some applications laser rays are propagating through a virtual composite mesh consisting of the finest resolution representation of the modeled space. A new 2nd order accurate diffusion solver has been implemented for the thermal conduction and radiation transport packages. One application area is the modeling of laser/target effects including debris/shrapnel generation. Other application areas include warm dense matter, EUV lithography, and material wall interactions for fusion devices.

Surface tension models for a multi-material ALE code with AMR

“…Recently, we described our work on combining ALE and Adaptive Mesh Refinement (AMR) [5] . The introduction of AMR into the more traditional ALE formulation allows users to choose the appropriate method given the geometry of the problem as well as the physics of the material states in the problem.…”

An AMR Capable Finite Element Diffusion Solver for ALE Hydrocodes

“…Modeling based on Arbitrary Lagrange Eulerian (ALE) hydrodynamics has a long track record of providing valuable insights through simulation for experimental programs. For instance hydrocodes have been used extensively at the National Ignition Facility (NIF) to model ignition target behavior during [1] and after the delivery of laser power [2,3] . Over the years, the complexity of these codes has grown as modeling of additional physics packages has been introduced.…”