An hybrid unstructured finite-volume algorithm for road vehicle flow computations with ground effects

Abstract

Grid generation is one of the main difficulties for road vehicle flow computations, and ground proximity effects are unavoidable part of automobile aerodynamics. A hybrid unstructured Navier-Stokes method is presented for the simulation of the incompressible turbulent flows around vehicle bodies. And a ground effect model is given out to investigate the ground effects numerically. RNG-κ-E model is used for turbulence closure. The hybrid grid system is composed of a structured grid for the outer large region of the computational domain, a structured or semi structured grid for the near-wall viscous region, and an unstructured grid for the remainder of the computational domain. The incompressible Navier-Stokes equations are solved on the hybrid grid by a cell-vertex, central differencing finite volume method. The effects of the ground on the body flow distributions have been investigated using a simple car model configuration.