Numerical study of the aerodynamics of time-trial cycling helmets

Numerical study of the aerodynamics of time-trial cycling helmets

Fabien Beaumont  Redha Taiar  Guillaume Polidori  Hanane Zaidi  Frédéric Grappe 

Laboratoire de Thermomécanique GRESPI-EA4694, Université de Reims, campus moulin de la housse, Reims, France

Laboratoire de recherche en Turbulence, Département Mécanique et Ingénierie Industrielle, université de Toronto, Toronto, Canada

EA 4660, laboratoire C3S, unité des sports (U-Sports), Université de Franche-Comté, 25000 Besançon, France

Corresponding Author Email: 
fabien.beaumont@univ-reims.fr;redha.taiar@univ-reims.fr;guillaume.polidori@univ-reims.fr; hanane.zaidi@utoronto.ca;frederic.grappe@univ-fcomte.fr
Page: 
33-50
|
DOI: 
https://doi.org/10.3166/i2m.16.1-4.33-50
Received: 
|
Accepted: 
|
Published: 
31 December 2017
| Citation

ACCESS

Abstract: 

The aerodynamic drag of three different time-trial cycling helmets is analyzed numerically from two different cyclist head positions. Computational Fluid Dynamics (CFD) methods  were  used  to  investigate  the  detailed  airflow  patterns around  the  cyclist  for  a constant  velocity  of  15m/s  without  wind.  CFD  simulations  were  used  to  study  the aerodynamic drag of the cyclist/helmet system which is closely related to the distribution of shear and pressure coefficients. We show that for a given head position, the helmet shape, by itself, has a  weak effect on  a cyclist’s aerodynamic performance (<1.5%). However, by varying head position, a cyclist significantly influences aerodynamic performance, the maximum difference between both positions being about 6.4%. CFD results have also shown that both helmet shape and head position significantly influence drag forces, pressure and wall shear stress distributions on the whole cyclist’s body due to the change in the near-wake behavior  and  in  location  of  corresponding  separation  and  attachment areas around  the cyclist

 

Keywords: 

Computational Fluid Dynamics (CFD), time trial helmets, aerodynamic drag

1. Introduction
2. Méthode
3. Résultats
4. Conclusion
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