Computational study of wake structure and base pressure on a generic SUV model

A study has been made of the accuracy and efficiency of steady and unsteady CFD methodologies when applied to the flow around a scale model generic SUV. Comparisons are made, predominantly in the wake region, against PIV and surface pressure data. These include RANS, URANS, and DES solvers with CD-Adapco’s Star-CCM+ and the open source code, OpenFOAM alongside the Lattice-Boltzmann approach of Exa’s PowerFLOW. The deficiencies of using a steady state RANS methodology for an inherently unsteady flow are highlighted by inaccuracies in the base surface pressures and locations of the wake vortex structures. Time dependent DES and LES approaches present the closest match to the experimental data, but these methods come with the highest cost. Variations across codes employing the same solvers are restricted to computational cost and not solution accuracy.