S. Parameswaran et al., FLOW STRUCTURE AROUND A 3D BLUFF-BODY IN-GROUND PROXIMITY - A COMPUTATIONAL STUDY, Journal of wind engineering and industrial aerodynamics, 46-7, 1993, pp. 791-800
A computational model is developed to help the automotive design engin
eer to optimize the body shape with minimum wind tunnel testing. Unste
ady, Reynolds-averaged, Navier-Stokes equations are solved numerically
by a finite-volume method and applied to study the flow around GM's v
ehicle-like body. The standard k-epsilon model is employed to model th
e turbulence in the flow. The finite volume equations are formulated i
n a strong conservative form on a three-dimensional, unstructured grid
system. The resulting equations are then solved by an implicit, time
marching, pressure-correction based algorithm. The steady state soluti
on is obtained by taking sufficient time steps until the flow field ce
ases to change with time within a prescribed tolerance. For the pressu
re-correction equation, preconditioned conjugate gradient method is em
ployed to obtain the solution. Most of the essential features of the f
low field around a bluff body in ground proximity, such as the formati
on of trailing vortices and the reverse flow region resulting from sep
aration, were well predicted. In addition, the variation of drag coeff
icient with Reynold's number per meter faithfully follows the experime
ntally observed pattern.