Abstract: Complex flow with large-scale moving boundaries is divided into a moving boundary zone and a common flow zone connected by a special interior boundary named zone interface. Local remeshing method is applied to deal with grid-reforming of a high-speed bullet. The axis is defined as a special grid-deforming boundary to avoid negative volume of grid near the axis. Arbitrary Lagrangian-Eulerian (ALE) formulation is used to solve unsteady process of a bullet leaving a muzzle. It indicates that the bullet is accelerated and then decelerated gradually.

Key words: large-scale moving boundary, zone interface, local remeshing, grid-deforming boundary, axis symmetrical ALE formuation, muzzle flow