Radiation Hydrodynamics Code LARED-H for Laser Fusion Simulation

LARED-H is a radiation hydrodynamics code in rz-cylindrical coordinates, developed for numerical simulation of laser inertial confinement fusion (ICF) in Institute of Applied Physics and Computational Mathematics (IAPCM). LARED-H is built on JASMIN, IAPCM’s adaptive structured mesh applications infrastructure. Currently, LARED-H can accomplish the integrated simulation of ignition target. Because structured grid can not handle the complicated geometry and multi-material configuration of ICF, multi-block structured grids are employed in LARED-H. Using multi-block grids, we can deal with complicated geometry and generate initial meshes with good quality. Large deformation of fluid is one of the most difficult issues of numerical simulation of laser fusion. In LARED-H code, the strategy of “Lagrange plus remapping” is used to resolve the extreme distortion of computational meshes. We allow the meshes move with fluid until they get tangled, and then transform the physical variables from the tangled meshes to new meshes. On the new meshes, the material interface is not necessary to maintain as Lagrangian curve and is allowed to cross the cells. Therefore, mixed cells are introduced. To model the mixed cells, interface tracing algorithms of material interface and mixture models are developed. To discrete the three-temperatures energy equations, Kershaw diffusion scheme is used. In our code, Kershaw diffusion scheme is extended from structured grids to multi-block girds according to continuous flux conditions. An ignition target is simulated by LARED-H code and numerical results are demonstrated.

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