Aerodynamic ground effect: a case study of the integration of CFD and experiments

Ground effect aerodynamics, although a subject of much interest to automotive, aircraft and naval architecture designers, is still an area of some uncertainty due to the problematic nature of experimental (and sometimes numerical) simulation. An integrated study, making use of both experimental (Particle Imaging Velocimetry) and numerical techniques (Computational Fluid Dynamics finite Volume solver), is used to demonstrate the effect and importance of the common assumptions and simulation issues. For certain important ground effect situations, it becomes clear that a numerical simulation is the only feasible option; however, a careful and systematic study of similar experiments is vital to gain the confidence required in the numerical solution. Only when this confidence has been gained, can the numerical simulation confidently be used for prediction of the experimentally unfeasible, but important, Situation. Three ambiguous areas of ground effect aerodynamics are identified, and it combination of numerical and experimental results presented.