Understanding the Aerodynamic Benefits of Drafting in the Wake of Cyclists

• Main Authors: Christopher Brown, Timothy Crouch, David Burton, Mark C. Thompson
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Proceedings
• Subjects: cycling aerodynamics; wake dynamics; speed sports; aerodynamic drag
• Online Access: https://www.mdpi.com/2504-3900/49/1/32

A new approach is presented to characterize the aerodynamic benefit from riding in the wake of another cyclist at different downstream locations. The method presented uses the dynamic pressure deficit in the wake of a cycling mannequin to estimate percentage drag savings. In the experiments, the time-averaged velocity behind a cycling mannequin was recorded in 1 × 0.95 m cross-planes by two four-hole pressure (Cobra) probes for four static leg positions (0°, 90°, 180°, and 270°). It was found that the wake of the cycling mannequin propagated to one side or the other as it developed downstream, depending on the strength of the two large-scale counter-rotating streamwise vortical structures shed off the hips of the mannequin. In the near wake, the complex wake dynamics resulted in an inaccurate prediction of the relative drag reduction based upon a dynamic pressure deficit. However, as the wake developed and stabilised further downstream, the dynamic pressure deficit was found to provide a reasonable estimate of the aerodynamic drag reduction of riding in the wake of the lead rider.