Print Email Facebook Twitter The Ring of Fire for in-Field Sport Aerodynamic Investigation Title The Ring of Fire for in-Field Sport Aerodynamic Investigation Author Spoelstra, A.M.C.M.G. (TU Delft Aerodynamics) Terra, W. (TU Delft Aerodynamics) Sciacchitano, A. (TU Delft Aerodynamics) Contributor Espinosa, Hugo G. (editor) Rowlands, David R. (editor) Shepherd, Jonathan (editor) Thiel, David V. (editor) Date 2018 Abstract 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. Subject speed sportscyclingaerodynamic dragin-field measurement system To reference this document use: http://resolver.tudelft.nl/uuid:10b2ac63-b7ed-4a57-8b7f-0fe67a23769a DOI https://doi.org/10.3390/proceedings2060221 Publisher MDPI Source Proceedings of the 12th Conference of the International Sports Engineering Association (ISEA 2018): Engineering of Sport Event ISEA 2018: 12th Conference of the International Sports Engineering Association 'Engineering of Sport', 2018-03-26 → 2018-03-28, Brisbane, Australia Series Proceedings, 2504-3900, 2 (6) Part of collection Institutional Repository Document type conference paper Rights © 2018 A.M.C.M.G. Spoelstra, W. Terra, A. Sciacchitano Files PDF proceedings_02_00221.pdf 1.29 MB Close viewer /islandora/object/uuid:10b2ac63-b7ed-4a57-8b7f-0fe67a23769a/datastream/OBJ/view