An accurate and efficient method for automatic deformation of unstructured polyhedral grids to simulate the flow induced by the motion of solid objects

摘要

In the present study, an efficient numerical method to deform an unstructured polyhedral grid for accurate simulations of a flow induced by a moving solid object is proposed. In order to overcome inefficiency of the existing methods based on the vertices of a computational cell, the present approach deforms the polyhedral grids adaptively using a network based on the centre of each computational cell. It is shown that the proposed method provides with an improved efficiency for an arbitrary Lagrangian-Eulerian (ALE) simulation of a flow with a moving solid object compared to the existing methods based on the vertices. It is also shown that a polyhedral grid results in a better numerical accuracy than a triangular grid. The present numerical methods were applied to flows around a fixed and oscillating circular cylinder with various Reynolds numbers and oscillating frequencies. The produced numerical results were verified against aerodynamic characteristics of the previous numerical studies.