Three-Dimensional Moving Embedded-Grid Method for the Simulation of Flows Driven by Multiple Obstacles Traveling Long Distances(Fluids Engineering)

The purpose of this paper is to construct and develop the Moving Embedded-Grid method for simulation of three-dimensional incompressible flows including obstacles traveling long distance. The feature of the presented method is that the Embedded-Grid can move without restriction in all directions in a stationary main grid covering the whole of the flow field. The method is 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. First of all, it is confirmed that the present method satisfies the geometric conservation law. Next, the method has been applied to the flow around a sphere traveling long distance in a stationary fluid and the result shows good agreement with other reference solution. The method has been applied to the flow in a mixer in order to investigate the effective scheme of stirring two fluids by rods and the unsteady behavior of the flow is shown. The results show the promising feature of the method.