Optimising Time Trial Helmet Design for Enhanced Aerodynamics in Cycling Through CFD Techniques

Campbell, Robert (2024) Optimising Time Trial Helmet Design for Enhanced Aerodynamics in Cycling Through CFD Techniques. [USQ Project]

Text (Project – redacted) CAMPBELL_R_Dissertation_Redacted.pdf Download (21MB)

Abstract

Throughout the history of cycling, advancements in aerodynamics through design have given the rider ‘free’ speed without having to exert any additional energy. In the context of professional cycling, athletes and their multi-million-dollar budget teams are striving to gain any advantage over competitors through aerodynamics in the form of improved design, clothing, helmets, shoes, socks, and of course the sleek shaved legs that most professional cyclists show off in the peloton. The first race that shocked the world for aerodynamics was the 1989 Tour De France. This final stage consisted of a 25 km TT event, in which Greg Lemond went from second to first place by utilising a TT helmet, disc wheel and ‘aero’ bars, something unheard of at the time.

The literature review provided the governing equations to construct a theoretical model to set a reference for helmet dimensions and performance. From this, a TT time savings model was derived to show how the helmets performed over a 40km TT when used by a rider of the same size and output of 400 W. ANSYS Spaceclaim was used to design a control helmet for testing to set a reference point for all other helmets. Three commercially available designs were replicated for testing which included the BELL Javelin, HJC Adwatt and POC Tempo. Three prototypes were designed and tested against the replicas. ANSYS Fluent was selected to perform the simulations at a velocity of 13 m/s (46.8 km/h) utilising a " − $ model to maintain computational efficiency and an appropriate wake and enclosure dimensions were defined. The simulations included the use of a human model which consisted of a larger male size torso, arms and head only, in which simulations for each helmet were performed at angles of 20 and 30 degrees.

Overall, the top performing helmet was the version 3 prototype at 20 degrees with a 13.7% efficiency improvement than the control helmet. When ranked in the TT time savings model it was 15.15 seconds in front of second place and 48.48 seconds in front of last place. The worst performing helmet was the BELL Javelin at 30 degrees. Further work was identified to validate the results from this research which included 3D printed prototyping helmets for WT testing followed by human testing in WT and on road testing. The main finding was that helmet performance is heavily reliant on rider position and yaw angle, even in extreme or irregular designs. Further designs would need to consider this with the potential for future projects of technology which provides data to the cyclist in real time on how to adjust their position whilst riding to obtain an optimal aerodynamic efficiency.

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Item Type:	USQ Project
Item Status:	Live Archive
Faculty/School / Institute/Centre:	Current – Faculty of Health, Engineering and Sciences - School of Engineering (1 Jan 2022 -)
Supervisors:	Wandel, Andrew
Qualification:	Bachelor of Engineering (Honours)
Date Deposited:	07 Oct 2025 01:05
Last Modified:	07 Oct 2025 01:28
Uncontrolled Keywords:	Cycling, road cycling, sports engineering, aerodynamics, mechanical engineering; computational fluid dynamics; CFD; bicycle; helmet; time trial
URI:	https://sear.unisq.edu.au/id/eprint/53022

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