Numerical study for flow over a realistic generic model, DrivAer, using URANS

Abstract

The aim of this study is to present a systematic approach for the grid convergence analysis in simulating flow around a realistic generic model, DrivAer. The numerical simulation is modelled using unsteady Reynolds Averaged Navier-Stokes (URANS) equation. A minimum of three different grid resolutions are considered, which are fine, medium and coarse in order to investigate the grid independency. Richardson extrapolation and Grid Convergence Index (GCI) are introduced to quantitatively evaluate the grid independency. Based on the results between those three different grids, a monotonic convergence criteria has been achieved. The reduction in GCI value indicates that the grid convergence error has been significantly reduced, in which the fine grid has a GCI value less than 7%. Additionally, the result from the fine grid is only 6% difference if compared with previous experimental study.