TY - GEN
T1 - The Ring of Fire for in-Field Sport Aerodynamic Investigation
AU - Spoelstra, Alexander
AU - Terra, Wouter
AU - Sciacchitano, Andrea
PY - 2018
Y1 - 2018
N2 - 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.
AB - 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.
KW - speed sports
KW - cycling
KW - aerodynamic drag
KW - in-field measurement system
UR - http://resolver.tudelft.nl/uuid:10b2ac63-b7ed-4a57-8b7f-0fe67a23769a
U2 - 10.3390/proceedings2060221
DO - 10.3390/proceedings2060221
M3 - Conference contribution
T3 - Proceedings
BT - Proceedings of the 12th Conference of the International Sports Engineering Association (ISEA 2018)
A2 - Espinosa, Hugo G.
A2 - Rowlands, David R.
A2 - Shepherd, Jonathan
A2 - Thiel, David V.
PB - MDPI
T2 - ISEA 2018: 12th Conference of the International Sports Engineering Association 'Engineering of Sport'
Y2 - 26 March 2018 through 28 March 2018
ER -