Abstract
In this paper, two moving mesh methods are introduced. One is a Trans-mesh method and the other is a Moving Computational Domain method. In the Trans-mesh method, the bodies can move freely in a main mesh that covers the entire flow field. On the other hand, in the Moving Computational Domain method, the whole of the computational domain including bodies inside moves in the physical space without the limit of region size. These methods are constructed based on the four-dimensional control volume in space-time unified domain such that the method assures to be divergence-free in the space-time unified domain and thus satisfies both the physical and geometrical conservation laws simultaneously. The methods are applied to a falling sphere by gravity in an infinite long straight pipe and an infinite long bending pipe. The results indicate that these methods are promising in simulating the interaction of incompressible fluid-rigid body with collisions.
