Aerodynamic analysis of different cyclist hill descent positions
Aerodynamic analysis of different cyclist hill descent positions
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DOI：
10.1016/j.jweia.2018.08.010
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发表时间：
2018-10-01
影响因子：
4.8
通讯作者：
Andrianne, Thomas
中科院分区：
文献类型：
--
作者：
Blocken, Bert;van Druenen, Thijs;Andrianne, Thomas
不同的职业自行车手使用不同的下坡姿势，这表明在本研究之前，对于哪种姿势真正更好并没有共识，并且大多数自行车手没有测试不同的姿势，例如在风洞中，找出哪种姿势会给他们带来最大的优势。本文对15种不同的下坡位置进行了气动分析。假设山坡足够陡峭，不需要踩踏板来加速，并且下降过程中不包括需要改变位置的急转弯。利用三维RANS方程和Transition SST k-omega模型进行计算流体动力学（CFD）仿真。仿真结果验证了风洞测量结果。从锋面面积、阻力面积和表面压力系数三个方面对结果进行了分析。结果表明，在2016年环法自行车赛第8赛段Peyresourde下坡时，臭名昭著的“Froome”位置在空气动力学上并不比其他几个位置优越。其他姿势的速度要快7.2%，而且也更安全，因为它们在两个车轮上提供了更均匀的体重分配。此外，一些位置允许更大的发电量在空气动力学上是优越的。
Different professional cyclists use very different hill descent positions, which indicates that prior to the present study, there was no consensus on which position is really superior, and that most cyclists did not test different positions, for example in wind tunnels, to find which position would give them the largest advantage. This paper presents an aerodynamic analysis of 15 different hill descent positions. It is assumed that the hill slope is steep enough so pedaling is not required to gain speed and that the descent does not include sharp bends necessitating changes in position. The analysis is performed by Computational Fluid Dynamics (CFD) simulations with the 3D RANS equations and the Transition SST k-omega model. The simulations are validated wind tunnel measurements. The results are analyzed in terms of frontal area, drag area and surface pressure coefficient. It is shown that the infamous "Froome" position during the Peyresourde descent of Stage 8 of the 2016 Tour de France is not aerodynamically superior to several other positions. Other positions are up to 7.2% faster and also safer because they provide more equal distribution of body weight over both wheels. Also several positions that allow larger power generation are aerodynamically superior.