An optimized multi-time-step interpolation scheme for overset gridS

A multi-time-step algorithm for overset grids is presented based on an optimized time interpolation scheme in this paper. Time interpolation is adopted in the interface between adjacent blocks, which are marching in time with different time steps required by the local numerical stability. There is no strict constraint on the ratio of mesh sizes between neighboring blocks. This can alleviate the burden of the grid generation for multi-time-step marching methods. The optimized time interpolation scheme can be simply combined with existing time marching schemes to achieve multi-time-step marching for overset grids. A number of examples are presented to demonstrate the feasibility and efficiency of the proposed algorithm.