Wang He, Wang Jia-Dao, and Weng Ding. Aerodynamic drag analysis based on SST model bicycle helmet surface depression effect. Dynamic Systems and Applications 29 (2020) No. 9, 2721 – 2732

https://doi.org/10.46719/dsa20202991

ABSTRACT.
Aerodynamic drag is the primary resistance which influences the fishing time during the competitive cycling sports. In order to reduce the required energy loss and improve the performance of the competitive athletes, many aerodynamic cycling helmets have been designed to minimize the resistive forces. From large amount of experimental investigations, it has been observed that dimples on the upper surface of the objects can create turbulence which delays the flow separation and reduces the pressure drag. The paper uses the SST turbulence mathematical model to analyze the dimples with different depth ratios for some surface modification, and studies the aerodynamic drag reduction characteristics of the riding helmet. The detailed flow pattern and pressure distribution around head-helmet system with dimples and without dimples were simulated by making the use of CFD. The maximum ratio of aerodynamic drag reduction can reach up to 8%.

Keywords: Cycling helmet; dimple; aerodynamic drag; flow separation; SST model