Eulerian grid subdivision algorithm based on unsplit method

When dealing with the problems of multi-material interaction, hydrodynamics numerical methods of Euler is one of the most effective ways. When using unsplit method to deal with pure cells in Euler coordinate, mixed cells are subdivided based on Youngs' interface reconstruction algorithm which can avoid complicated transport calculation. This paper gives all of the possible distribution modes to eight neighboring cells of both pure ones and subdivided ones. In the end, this unsplit method is added into numerical simulation program of MMIC-2D universal multi-material two-dimension explosion and impact which is developed by ourselves. The simulation results verify that our method can not only improve calculation precision efficiently, but also reduce workload and save computation time.