Defraeye Thijs, Blocken Bert, Koninckx Erwin, Hespel Peter, Verboven Pieter, Nicolai Bart, Carmeliet Jan
J Biomech Eng. 2014 Jan;136(1):011005. doi: 10.1115/1.4025792.
In team pursuit, the drag of a group of cyclists riding in a pace line is dependent on several factors, such as anthropometric characteristics (stature) and position of each cyclist as well as the sequence in which they ride. To increase insight in drag reduction mechanisms, the aerodynamic drag of four cyclists riding in a pace line was investigated, using four different cyclists, and for four different sequences. In addition, each sequence was evaluated for two arm spacings. Instead of conventional field or wind tunnel experiments, a validated numerical approach (computational fluid dynamics) was used to evaluate cyclist drag, where the bicycles were not included in the model. The cyclist drag was clearly dependent on his position in the pace line, where second and subsequent positions experienced a drag reduction up to 40%, compared to an individual cyclist. Individual differences in stature and position on the bicycle led to an intercyclist variation of this drag reduction at a specific position in the sequence, but also to a variation of the total drag of the group for different sequences. A larger drag area for the group was found when riding with wider arm spacing. Such numerical studies on cyclists in a pace line are useful for determining the optimal cyclist sequence for team pursuit.
在团体追逐赛中,一组骑自行车的人在队列中骑行时所受的阻力取决于几个因素,比如人体测量学特征(身高)、每个骑车人的位置以及他们骑行的顺序。为了更深入了解减阻机制,研究了四名骑车人在队列中骑行时的空气动力学阻力,使用了四名不同的骑车人,并设置了四种不同的顺序。此外,对每种顺序还评估了两种手臂间距情况。与传统的实地或风洞实验不同,本研究采用了一种经过验证的数值方法(计算流体动力学)来评估骑车人的阻力,模型中未包含自行车。骑车人的阻力明显取决于其在队列中的位置,与单独骑车的人相比,排在第二位及后续位置的人所受阻力可降低达40%。身高和自行车上位置的个体差异导致在序列中的特定位置,骑车人间的这种阻力降低存在差异,同时也导致不同序列中团体总阻力的变化。当手臂间距更宽时,发现团体的阻力面积更大。这种对队列中骑车人的数值研究有助于确定团体追逐赛的最佳骑车人顺序。