Experimental and Computational Study of the Flow around a Stationary and Rotating Isolated Wheel and the Influence of a Moving Ground Plane 2019-01-0647
This study investigates the aerodynamic behaviour of the flow around a rotating and stationary 60% scale isolated wheel, without the use of a moving ground plane. The aim of this research was to further improve the understanding of the fundamental aerodynamic flow features and how wheel rotation and moving ground planes modify these. Wind tunnel tests were used to measure force coefficients and provide aerodynamic data through the use of Particle Image Velocimetry (PIV) and were performed over a range of pre to post critical Reynolds numbers, with the wheel driven by a rotating drum system. The experimental data was used to validate unsteady CFD calculations using STAR-CCM+. A K-Omega SST Improved Delayed Detached Eddy Simulation (IDDES) turbulence model was found to outperform other models by capturing an increased amount of finer detailed, high frequency vortical structures whilst also showing a good agreement with the experimental results. The CFD and experimental data illustrated large scale structural differences in the surrounding flow for both the stationary and rotating cases due to varying flow separations induced by each configuration. The rotating model also exhibited a lower drag at post critical Reynolds numbers, which is corroborated by existing literature. Importantly, the CFD conducted showed minimal difference between a stationary and moving ground plane simulation with a rotating wheel, suggesting that as long as the wheel is rotating, valid experiments can be performed without the complexity of a moving ground plane.