Gridless Boundary Treatment for Viscous Flow Computations Using Cartesian Grid Method

Abstract

A realistic wall boundary treatment method for viscous flow computations using Cartesian grid method is proposed to simulate compressible flows around complex geometries at low and high Reynolds numbers. In this method, a Cartesian grid is used as a background grid to cover the whole computational domain and a wall boundary is treated by gridless method to express a smooth wall boundary of input geometries in a Cartesian grid. Subgrid which is similar to a prismatic layer in conventional unstructured grid method is introduced near the wall boundary to resolve a boundary layer. The proposed method is applied to the Building-Cube Method (BCM) which is a block-structured Cartesian grid approach proposed by one of the authors. Capability of the proposed method is demonstrated through several two-dimensional test cases.