A parallel, multigrid overset grid flow solver using implicit hole cutting

Abstract

In the computation of flow over complex configurations, the use of overset grids eases the grid generation process, but the non trivial task of ensuring communication between the overlapping grids must first be established. This need is efficiently addressed by using a new practically useful Implicit Hole Cutting (IHC) method introduced by Lee and Baeder. This approach, is a cell selection process based on the main criterion of cell size, and all grid points including hole interior points and hole fringe points, are treated indiscriminately in the flow computation. Potentially these features ease the implementation of the multigrid algorithms which are rarely used in overset methods. It can also be combined well with parallel computing to improve the computational efficiency and turn-around-time of the flow solver. The present study examines the use of IHC method as an inter-grid communication method within a framework amenable for the implementation of a multigrid method and parallel computation. The convergence, accuracy and efficiency of the current solver are assessed particularly for the large-scale computations of realistic aerodynamic configurations. Both viscous and inviscid computations are examined. The results here show promise but the overall performance of the solver is, as common to other flow solver, grid quality dependent.