The time step control in two-dimensional three-temperature hydrodynamic calculations is studied.Based on numerical stability and accuracy we propose several conditions that restrict the time step.These conditions change the time step automatically in computation so that the calculation proceeds with the most economical and reasonable time step.Numerical results are shown to demonstrate the efficiency of the method.

An effective rezoning method for two-dimensional Lagrange meshes, i.e., an integral conservative remapping method, is studied. The algorithm is described in detail. Calculation results are shown.