Computational analysis of three-dimensional turbulent flow around a bluff body in ground proximity

The Reynolds-averaged Navier-Stokes equations, together with the equations of the k-e model of turbulence, were solved numerically in a general curvilinear coordinate system for three-dimensional turbulent flows around Ahmed's vehicle-like body. The numerical computations were performed for various afterbody upper-surface slant angles at a constant Reynolds number of 4.3 x 10 based on the body length. A multistep correction procedure was incorporated into the incompressibility condition, and the solution of the Poisson equation for pressure was obtained from the conjugate gradient method. A second-order discretization scheme for the convection term was applied to reduce the numerical diffusion. Most of the essential measured features of the flowfield around Ahmed's vehicle-like body in ground proximity, such as the formation of trailing vortices and the reverse flow region resulting from separation, were well predicted.