Aerodynamics of transiting objects via large-scale PIV - the Ring of Fire Concept

Aerodynamics of transiting objects via large-scale PIV - the Ring of Fire Concept

Spoelstra, Alexander (TU Delft Aerospace Engineering)

Sciacchitano, A. (mentor)
Terra, W. (mentor)

Delft University of Technology

Aerospace Engineering

2017-10-24

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 3.17 × 10^5. The measurements upstream and approximately 1000 × 1700 m^2. The non-dimensional, phase-locked, time-averaged streamwise velocity fields compare well to literature and the time-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 significant 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, instead, matches literature well.

Speed sports
Cycling
Aerodynamic drag
in-field measurement system
large-scale PIV
HFSB

http://resolver.tudelft.nl/uuid:73bcc7a8-68b9-4e5b-b79a-65f41fc45bbb

2021-11-01

Student theses

master thesis

© 2017 Alexander Spoelstra