Dynamic implicit 3D adaptive mesh refinement for non-equilibrium radiation diffusion

Solution of Equilibrium Radiation Diffusion Problems Using Implicit Adaptive Mesh Refinement

Diffusion approximations to radiation transport feature a nonlinear conduction coefficient that leads to formation of a sharp front, or Marshak wave, under suitable initial and boundary conditions. The front can vary several orders of magnitude over a very short distance. Resolving the shape of the Marshak wave is essential, but using a global fine mesh can be prohibitively expensive. In such c...

Dynamic Adaptive Mesh Refinement for Topology Optimization

We present an improved method for topology optimization with both adaptive mesh refinement and derefinement. Since the total volume fraction in topology optimization is usually modest, after a few initial iterations the domain of computation is largely void. Hence, it is inefficient to have many small elements, in such regions, that contribute significantly to the overall computational cost but...

Implicit adaptive mesh refinement for 2D reduced resistive magnetohydrodynamics

An implicit structured-adaptive-mesh-refinement (SAMR) solver for 2D reduced magnetohydrodynamics (MHD) is described. The time-implicit discretization is able to step over fast normal modes, while the spatial adaptivity resolves thin, dynamically evolving features. A Jacobian-free Newton-Krylov method is used for the nonlinear solver engine. For preconditioning, we have extended the optimal “ph...

Parallel 3D Adaptive Mesh Refinement in Titanium

Solution of Reduced Resistive Magnetohydrodynamics using Implicit Adaptive Mesh Refinement

Computational study of the macroscopic stability of plasmas is a challenging multi-scale problem. Implicit time integration can be used to relieve stability constraints due to fast Alfvén waves, and adaptive mesh refinement (AMR) can be used to resolve highly localized solution features. The strong nonlinearities and numerical stiffness of magnetohydrodynamics (MHD) models present further chall...