Jackson P S
Department of Mechanical Engineering, University of Auckland, New Zealand.
J Sports Sci. 1995 Jun;13(3):239-45. doi: 10.1080/02640419508732233.
This paper sets out the effects of the various factors which determine the speed of racing kayaks and canoes, with the aim of identifying the areas most likely to lead to improvements. The friction, wave and aerodynamic components of hull drag are first described in terms of the hull parameters, in order to provide accurate predictions of propulsive power as a function of hull speed. The generation of thrust by paddling is described via the mechanics of vortex-ring wakes, in order to determine the propulsive efficiency in terms of the parameters describing the blade and stroke. Equating the thrust and drag then leads to reliable estimates of the mechanical power actually delivered by a canoeist. The earlier analysis then leads to a predictive model for hull speed in terms of all the parameters describing the hull and blade performance. This is used to determine the sensitivity of hull speed to small changes in each parameter, enabling the most important factors to be identified. The paper concludes with a discussion of the various improvements to kayaks that have actually appeared in recent years, and uses the earlier analysis to explain and predict the resulting speed changes.
本文阐述了决定赛艇和皮划艇速度的各种因素的影响,目的是找出最有可能带来速度提升的方面。首先根据船体参数描述了船体阻力的摩擦、波浪和空气动力学成分,以便准确预测推进功率与船体速度的函数关系。通过涡环尾流的力学原理描述划桨产生的推力,从而根据描述桨叶和划桨动作的参数确定推进效率。使推力和阻力相等进而得出皮划艇运动员实际输出的机械功率的可靠估计值。早期的分析进而得出一个根据描述船体和桨叶性能的所有参数预测船体速度的模型。这用于确定船体速度对每个参数微小变化的敏感度,从而找出最重要的因素。本文最后讨论了近年来赛艇实际出现的各种改进,并利用早期的分析来解释和预测由此产生的速度变化。