Impact of a motorcycle on cyclist aerodynamic drag in parallel and staggered arrangements

Bert Blocken; Stefanie Gillmeier; Fabio Malizia; Thijs van Druenen

doi:10.1007/s12283-021-00344-3

Impact of a motorcycle on cyclist aerodynamic drag in parallel and staggered arrangements

Bert Blocken (Corresponding author), Stefanie Gillmeier, Fabio Malizia, Thijs van Druenen

Research output: Contribution to journal › Article › Academic › peer-review

5 Citations (Scopus)

Abstract

Cycling races contain a multitude of motorcycles for various activities including television broadcasting. During parts of the race, these motorcycles can ride in close proximity of cyclists. Earlier studies focused on the impact of a nearby motorcycle on cyclist drag for in-line arrangements. It was shown that not only a motorcycle in front of a cyclist but also a motorcycle closely behind a cyclist can substantially reduce cyclist drag. However, there appears to be no information in the scientific literature about the impact of the motorcycle on cyclist drag for parallel and staggered arrangements. This paper presents wind tunnel measurements of cyclist drag for 32 different parallel and staggered cyclist-motorcycle arrangements. It is shown that the parallel arrangement leads to a drag increase for the cyclist, in the range of 5 to about 10% for a lateral distance of 2 to 1 m. The staggered arrangement can lead to either a drag increase or a drag decrease, where the latter is about 2% for most positions analyzed. For one of the parallel arrangements, computational fluid dynamics simulations were performed to provide insight into the reasons for the drag increase. A cyclist power model was used to convert the drag changes into potential time gains or losses. Compared to a lone cyclist riding at a speed of 46.8 km/h (13 m/s) on level road in calm weather, the time loss by a drag increase of 10%, 4% and − 2% was 2.16, 0.76 s and − 0.80 s per km, respectively. These time differences are large enough to influence the outcome of cycling races.

Original language	English
Article number	7
Number of pages	11
Journal	Sports Engineering
Volume	24
Issue number	1
DOIs	https://doi.org/10.1007/s12283-021-00344-3
Publication status	Published - 7 Apr 2021

Bibliographical note

Funding Information:
We thank the technical support team of the Wind Tunnel Laboratory at the Department of the Built Environment at Eindhoven University of Technology: Ing. Jan Diepens, Geert-Jan Maas and Stan van Asten. This work was also sponsored by NWO Exacte en Natuurwetenschappen (Physical Sciences) for the use of supercomputer facilities, with financial support from the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (Netherlands Organization for Scientific Research, NWO). We acknowledge the partnership with Ansys CFD.

Funding Information:
We thank the technical support team of the Wind Tunnel Laboratory at the Department of the Built Environment at Eindhoven University of Technology: Ing. Jan Diepens, Geert-Jan Maas and Stan van Asten. This work was also sponsored by NWO Exacte en Natuurwetenschappen (Physical Sciences) for the use of supercomputer facilities, with financial support from the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (Netherlands Organization for Scientific Research, NWO). We acknowledge the partnership with Ansys CFD.

Publisher Copyright:
© 2021, The Author(s).

Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.

Funding

We thank the technical support team of the Wind Tunnel Laboratory at the Department of the Built Environment at Eindhoven University of Technology: Ing. Jan Diepens, Geert-Jan Maas and Stan van Asten. This work was also sponsored by NWO Exacte en Natuurwetenschappen (Physical Sciences) for the use of supercomputer facilities, with financial support from the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (Netherlands Organization for Scientific Research, NWO). We acknowledge the partnership with Ansys CFD. We thank the technical support team of the Wind Tunnel Laboratory at the Department of the Built Environment at Eindhoven University of Technology: Ing. Jan Diepens, Geert-Jan Maas and Stan van Asten. This work was also sponsored by NWO Exacte en Natuurwetenschappen (Physical Sciences) for the use of supercomputer facilities, with financial support from the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (Netherlands Organization for Scientific Research, NWO). We acknowledge the partnership with Ansys CFD.

Keywords

Aerodynamic cyclist drag
Computational fluid dynamics
Cycling aerodynamics
Motorbike
Wind tunnel

Access to Document

10.1007/s12283-021-00344-3

Cite this

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title = "Impact of a motorcycle on cyclist aerodynamic drag in parallel and staggered arrangements",

abstract = "Cycling races contain a multitude of motorcycles for various activities including television broadcasting. During parts of the race, these motorcycles can ride in close proximity of cyclists. Earlier studies focused on the impact of a nearby motorcycle on cyclist drag for in-line arrangements. It was shown that not only a motorcycle in front of a cyclist but also a motorcycle closely behind a cyclist can substantially reduce cyclist drag. However, there appears to be no information in the scientific literature about the impact of the motorcycle on cyclist drag for parallel and staggered arrangements. This paper presents wind tunnel measurements of cyclist drag for 32 different parallel and staggered cyclist-motorcycle arrangements. It is shown that the parallel arrangement leads to a drag increase for the cyclist, in the range of 5 to about 10% for a lateral distance of 2 to 1 m. The staggered arrangement can lead to either a drag increase or a drag decrease, where the latter is about 2% for most positions analyzed. For one of the parallel arrangements, computational fluid dynamics simulations were performed to provide insight into the reasons for the drag increase. A cyclist power model was used to convert the drag changes into potential time gains or losses. Compared to a lone cyclist riding at a speed of 46.8 km/h (13 m/s) on level road in calm weather, the time loss by a drag increase of 10%, 4% and − 2% was 2.16, 0.76 s and − 0.80 s per km, respectively. These time differences are large enough to influence the outcome of cycling races.",

keywords = "Aerodynamic cyclist drag, Computational fluid dynamics, Cycling aerodynamics, Motorbike, Wind tunnel",

author = "Bert Blocken and Stefanie Gillmeier and Fabio Malizia and {van Druenen}, Thijs",

note = "Funding Information: We thank the technical support team of the Wind Tunnel Laboratory at the Department of the Built Environment at Eindhoven University of Technology: Ing. Jan Diepens, Geert-Jan Maas and Stan van Asten. This work was also sponsored by NWO Exacte en Natuurwetenschappen (Physical Sciences) for the use of supercomputer facilities, with financial support from the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (Netherlands Organization for Scientific Research, NWO). We acknowledge the partnership with Ansys CFD. Funding Information: We thank the technical support team of the Wind Tunnel Laboratory at the Department of the Built Environment at Eindhoven University of Technology: Ing. Jan Diepens, Geert-Jan Maas and Stan van Asten. This work was also sponsored by NWO Exacte en Natuurwetenschappen (Physical Sciences) for the use of supercomputer facilities, with financial support from the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (Netherlands Organization for Scientific Research, NWO). We acknowledge the partnership with Ansys CFD. Publisher Copyright: {\textcopyright} 2021, The Author(s). Copyright: Copyright 2021 Elsevier B.V., All rights reserved.",

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Impact of a motorcycle on cyclist aerodynamic drag in parallel and staggered arrangements

Abstract

Bibliographical note

Funding

Keywords

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Atmospheric Boundary Layer Wind Tunnel

Cite this

Impact of a motorcycle on cyclist aerodynamic drag in parallel and staggered arrangements

Abstract

Bibliographical note

Funding

Keywords

Access to Document

Other files and links

Fingerprint

Equipment

Atmospheric Boundary Layer Wind Tunnel

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