The Ring of Fire for in-Field Sport Aerodynamic Investigation

Proceedings

Spoelstra, Alexander¹ 

关键词: speed sports;    cycling;    aerodynamic drag;    in-field measurement system;   

DOI  :  10.3390/proceedings2060221

学科分类：社会科学、人文和艺术（综合）

来源: mdpi

【 摘 要 】

A novel measurement system, the Ring of Fire, is deployed which enables the aerodynamic drag estimation of transiting cyclists. The system relies upon the use of large-scale stereoscopic PIV and the conservation of momentum within a control volume in a frame of reference moving with the athlete. The rider cycles at a velocity of approximately 8 m/s, corresponding to a torso based Reynolds number of 3.2 × 105. The measurements upstream and in the wake of the athlete are conducted at a rate of 2 kHz within a measurement plane of approximately 1000 × 1700 mm2. The non-dimensional, ensemble-averaged streamwise velocity fields compare well to literature and the ensemble-averaged drag area shows a rather constant value along the wake with an uncertainty of 5%. A comparison with wind tunnel force balance measurements shows discrepancies which may be partly attributed to the bike supports and stationary floor in the wind tunnel measurements. The 25% drag difference measured between a rider in upright and time-trial position, however, matches literature well.

【 授权许可】

CC BY