Bicycle Wheel Aerodynamics Predictions Using CFD: Efficiency Using Blade Element Theory

Abstract

The cycling industry has long relied on expensive wind tunnel testing when designing aerodynamic products, particularly in the context of wheels which account for 10 to 15 percent of a cyclist’s total aerodynamic drag. With the recent advent of computational fluid dynamics, the industry now has an economical tool to supplement the wheel design process; however, the complex nature of rotating spoked wheels requires high resolution meshes to model at acceptable fidelity. This research investigates an alternative CFD method that lowers the computational cost of modeling aerodynamic bicycle wheels by modeling spokes using blade element momentum virtual disks. Two CFD models of a HED Trispoke wheel, one with resolved spokes (physical mesh) and one with modeled spokes (virtual disk), are compared to existing CFD and wind tunnel drag coefficient data at various headwind speeds and angles. Preliminary data shows good agreement