Experimental Investigation of the Flow Around a Generic SUV

The results of an experimental investigation of the flow in the near wake of a generic Sport Utility Vehicle (SUV) model are presented. The main goals of the study are to gain a better understanding of the external aerodynamics of SUVs, and to obtain a comprehensive experimental database that can be used as a benchmark to validate math-based CFD simulations for external aerodynamics. Data obtained in this study include the instantaneous and mean pressures, as well as mean velocities and turbulent quantities at various locations in the near wake. Mean pressure coefficients on the base of the SUV model vary from −0.23 to −0.1. The spectrum of the pressure coefficient fluctuation at the base of the model has a weak peak at a Strouhal number of 0.07. PIV measurements show a complex three-dimensional recirculation region behind the model of length approximately 1.2 times the width of the model. Turbulence properties are also reported, and the large-scale turbulent structure in the near wake is investigated using Proper Orthogonal Decomposition (POD) methods. The results suggest that the more energetic modes in the symmetry plane correspond to a vortex shedding process, and the more energetic modes in the center horizontal plane are a lateral flapping motion of the wake and a breathing mode of the mean recirculation region.