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Rauenzahn, Rick M

Publications and source records attributed to Rauenzahn, Rick M.

4 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2010

A Second Order Self-Consistent IMEX Method for Radiation Hydrodynamics

We present a second order non-linearly consistent implicit/explicit (methods that use com- bination of implicit/explicit discretizations are often referred to as IMEX (IMplicit/EXplicit) methods [2,1,3]) time integration technique for solving radiation hydrodynamics problems. The idea is to hybridize an implicit and an explicit discretization in a nonlinearly consis- tent way in order to achieve second order time convergent calculations. In this scope, the hydrodynamics equations are discretized explicitly making use of the capability of well- understood explicit schemes. On the other hand , the radiation diffusion part is solved implicitly. In the view of the non-linearly consistent IMEX method, the hydrodynamics equations are solved as part of the non-linear function evaluation within the framework of the Jacobian-Free Newton Krylov (JFNK) method [16,14]. This is to avoid order reductions in time convergence due to the operator splitting. We present results from several test prob- lems in order to validate the numerical order of the scheme. For each test, we established second order time convergence.

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