The second investigation explored the aerodynamics of underbody-equipped bluff bodies in ground-effect flow. Focus was on the influence of multiple surrounding elements (wheels) on underbody diffuser performance. Flow phenomena, such as trailing-edge diffuser separation and vortex development, and how they are affected by wheels and their wakes are discussed.
The third investigation explored flow structure predictions of motorcycle engines surrounded by interfering objects (wheel, forks, frame). CFD simulations isolated key factors influencing flow phenomenon and were useful in predicting the effects of modifications to the design.
“Fast-turnaround CFD” was found to yield robust and sufficiently accurate results for varied aerodynamic configurations useful for applied vehicle design. It accurately calculated CL in multiple configurations (less than 25% error) as well as successfully modeled flow field dynamics for single and multiple body situations. This was done in 2D with low y+, and in 3D with high y+ value models which were relatively easy to mesh and run. Limitations with the approach, such as inability to accurately predict CD, are discussed.
Citation: Desai, S., Leylek, E., Lo, C., Doddegowda, P. et al., "Experimental and CFD Comparative Case Studies of Aerodynamics of Race Car Wings, Underbodies with Wheels, and Motorcycle Flows," SAE Technical Paper 2008-01-2997, 2008, https://doi.org/10.4271/2008-01-2997. Download Citation
Sachin Desai, Emily Leylek, Chi-Man Betty Lo, Punith Doddegowda, Aleksandr Bychkovsky, Albert R. George