We develop an open void method of slide line, based on unstructured arbitrary N-polygon grids managed system and tied slide technology, for simulation of large deformation problem of frequently multi-medium loading and unloading. Validity verification was done with metal hit and leave model. Method of distinguishing point and grid's open or closed void state and calculating velocity of point on slide line is given. This slide technology extends open void method of traditional structured grid to unstructured arbitrary N-polygon grids, and keeps merit of no void connectivity and simulating interface well. It has capability of simulating open and closed interface in practical problem. We did test in metal hit and leave model with conditions of many grids, different velocity and multi-medium, which proves validity of the method.

An internal coupling condition which can guarantee the conservation of flux on the irregular patched grids for the domain decomposition method is given. The Euler equations are solved by using the finite Volume method combined with van Leer's flux vector splitting. The TVD character and second order accuracy are realized by adopting a new limiter function. Numerical examples are presented as well.