Beaumont F, Lestriez P, Estocq P, Taiar R, Grappe F, Polidori G
GRESPI, Research Group in Engineering Sciences, Université de Reims Champagne-Ardenne, Moulin de la Housse, 51687 Reims cedex 2, France.
GRESPI, Research Group in Engineering Sciences, Université de Reims Champagne-Ardenne, Moulin de la Housse, 51687 Reims cedex 2, France.
J Biomech. 2019 Jan 3;82:387-391. doi: 10.1016/j.jbiomech.2018.11.006. Epub 2018 Nov 20.
The main purpose of this study was to assess the influence of the environmental temperature on both the aerodynamic flow evolving around the bicycle and cycling power output. The CFD method was used to investigate the detailed flow field around the cyclist/bicycle system for a constant speed of 11.1 m/s (40 km/h) without wind. In complement, a mathematical model was used to determine the temperature-dependent power output in the range [-10; 40 °C]. The numerical investigation gives valuable information about the turbulent flow field in the cyclist's wake which evolves accordingly the surrounding temperature. A major result of this study is that the areas of overpressure upstream of the cyclist and of underpressure downstream of him are less extensive for a temperature of 40 °C compared to -10 °C. The results suggest that the aerodynamic braking effect of the bicycle is minimized when the air temperature is high, as a lower air density results in a reduction in drag on the cyclist. This study showed that the power required to maintain a constant speed is reduced when the temperature is high, the reason being a lower aerodynamic resistance.
本研究的主要目的是评估环境温度对自行车周围空气动力学流动以及骑行功率输出的影响。采用计算流体力学（CFD）方法，在无风条件下，以11.1米/秒（40公里/小时）的恒定速度研究骑行者/自行车系统周围的详细流场。此外，使用数学模型确定在[-10；40°C]范围内与温度相关的功率输出。数值研究给出了关于骑行者尾流中湍流场的有价值信息，该湍流场会随着周围温度而变化。本研究的一个主要结果是，与-10°C相比，在40°C的温度下，骑行者上游的超压区域和下游的负压区域范围更小。结果表明，当气温较高时，自行车的空气动力学制动效果最小化，因为较低的空气密度会导致骑行者所受阻力减小。本研究表明，当温度较高时，维持恒定速度所需的功率会降低，原因是空气动力学阻力较小。
