A bobsleigh run is typically split into two phases. The first is the start (push) phase, where the athletes accelerate the sled over a short distance to maximize the initial speed. This phase lasts about 7 seconds, covers roughly 40 meters, and reaches around 30 km/h. The second is the descent, which lasts about 60 seconds over approximately 1500 meters, with speeds up to ~130 km/h.
My internship focused on the descent phase, with particular attention to the women’s monobob, a discipline introduced at the 2022 Winter Olympic Games. The work was carried out at LadHyX (École Polytechnique) as part of Samy Ben Hamoudi’s PhD research, under the supervision of Professor Christophe Clanet.
First, I processed the wind-tunnel datasets and the 3D scans, and built an OpenFOAM-based digital twin of the wind-tunnel setup.
The resulting setup reproduces the aerodynamic behaviour of a monobob over the range of speeds observed on track. It can therefore be used to assess the impact of design and configuration changes, such as the athlete’s position in the sled, helmet shape, and trajectory-dependent effects.
The second part of my work focused on the La Plagne track in France. The track is about 1500 meters long with a total vertical drop of around 200 meters, and includes 19 turns with varying radii and banking, making it a complex environment for trajectory analysis and optimization. It is expected to be used during the 2030 Winter Olympic Games.
To model the track geometry, the National Institute of Geographic and Forest Information (IGN) produced a 3D scan using photogrammetry. By combining this geometric model with measurements collected during the 2022 World Cup, I reconstructed the trajectories followed by the bobsleighs.
This reconstruction, combined with the previously developed digital wind tunnel, provides a solid foundation for studying optimal trajectories. It will allow for a detailed analysis of aerodynamic interactions between the bobsleigh and the track, particularly identifying critical sectors where performance gains can be achieved through better control of the trajectory and the dynamics of the vehicle.
[Back to Homepage]List of publications
- Aerodynamics of bobsleighs, zenodo (2024), Maxime C.N. Roux, (DOI)
List of Talks and Conferences
- Sport Physics 2024, Rennes, December 2024 : Aerodynamics of bobsleighs: wind tunnel and CFD results, Maxime C.N. Roux, Samy Ben Hamoudi and Christophe Clanet, (abstract), (slides)