Feasibility of an innovative methodology for testing rowing shell/canoe/kayak performance, with application to numerical performance prediction

测试划艇壳/独木舟/皮划艇性能的创新方法的可行性，并应用于数值性能预测

• 批准号: EP/F00625X/1
• 负责人: Ian Campbell
• 金额: $ 3.88万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF00625X%2F1
• 关键词: Feasibility; innovative; methodology; testing; rowing

One way to improve the performance of UK competitors in rowing/paddling events is to improve the performance of their equipment; in particular the boat hulls. A lot of effort has been spent in improving the materials and construction of the hulls to make them lighter and stiffer. However comparatively little scientific effort has been spent on improving the shape of the hull to reduce the drag, especially in comparison with sailing events such as the Americas Cup. This seems particularly strange since small gains can make huge differences in results. In the mens' rowing events at the Athens Olympics, an increase in speed of 0.5% would have taken crews in six events from silver to gold medals; whilst an increase of 1% would take all eight crews from silver to gold, seven crews from bronze to gold, and even three crews from fourth place to gold. One of the few companies who have built boats based on a systematic research programme in the early 1990s, Vespoli, supplied the GB eight which won gold at the 2000 Sydney Olympics.Optimisation of conventional ships for reduced drag is generally quite well understood; computer-based drag prediction techniques are relatively accurate and reliable, whilst experiment testing methodology is also well established. However the challenges for rowed/paddles hulls are considerably greater. The propulsion of the boat is unsteady / so the thrust varies throughout the rowing/paddling stroke. This is partly due to the movement of the oars/paddles relative to the water, and partly due to the exchange of momentum between the athletes and the boat. As a consequence the speed of the boat varies throughout the stroke. In addition to this, the movement of the athletes backwards and forwards leads to a pitching motion, where the bow of the boat rises and falls. These unsteady effects lead to a variation in drag through the stroke, which makes prediction of drag considerably more difficult.Additionally, the depth of water in a typical man-made rowing facility is quite shallow. In shallow water there are some additional complications in predicting the wave system generated by the boat. This is important, since one component of the drag is related to the energy radiated from the boat through the waves generated.Since the gains which are sought by improved design are so small, the techniques used to assess designs must be highly accurate; therefore a scientific study of the design of rowing/paddling hull form for minimum drag must consider these extra effects in order to generate reliable and realistic results. The current proposal is aimed at establishing the feasibility of developing a scientific procedure which can be used to assess the performance of boats in a realistic manner, including the effects of varying speed, pitching and shallow water. The procedure consists of three components: a technique for testing model hulls in a test tank; a technique to allow the data to be analysed, and scaled to full scale, and a technique for predicting the drag numerically. An experiment rig will be designed, built and commissioned which will enable realistic motions of a scale model hull form in a test tank including both the speed variation and the pitching motion. Full-scale measurements will be made on boats being rowed; the data obtained will be used to examine the techniques for scaling the test-tank data to full scale. Finally a numerical method for unsteady drag prediction, currently under development, will be extended to address particular issues relevant to rowing/paddling hulls.If the method is feasible it is anticipated that future studies will include assessment of existing designs, and optimisation of hull-forms to produce faster boats by reducing drag under realistic conditions. It is also anticipated that fundamental understanding of these complex flow phenomena can be improved, leading to better prediction techniques for unsteady drag in the future

提高英国选手在赛艇/划艇项目中的表现的一种方法是提高他们的设备性能；尤其是船体。为了使船体更轻、更硬，在改进船体的材料和结构上花费了大量的精力。然而，在改进船体形状以减少阻力方面的科学努力相对较少，特别是与美洲杯这样的帆船赛事相比。这似乎特别奇怪，因为小的收获可以产生巨大的结果。在雅典奥运会的男子赛艇项目中，速度提高0.5%将使六项比赛的选手从银牌变成金牌；而增加1%将使所有8名选手从银牌变为金牌，7名选手从铜牌变为金牌，甚至3名选手从第四名变为金牌。Vespoli是上世纪90年代初为数不多的几家根据系统研究计划建造船只的公司之一，该公司为2000年悉尼奥运会上赢得金牌的英国8艇供货。传统船舶减少阻力的优化通常是很容易理解的；基于计算机的阻力预测技术相对准确和可靠，同时实验测试方法也很成熟。然而，对划桨船体的挑战要大得多。船的推进力是不稳定的/所以在整个划桨过程中推力是变化的。这部分是由于桨/桨相对于水的运动，部分是由于运动员和船之间的动量交换。因此，船的速度在整个行程中是变化的。除此之外，运动员前后的运动导致了一个俯仰运动，船首上升和下降。这些非定常效应导致整个行程的阻力变化，这使得阻力预测变得相当困难。此外，在一个典型的人造划船设施的水的深度是相当浅的。在浅水中，预测船所产生的波浪系统有一些额外的复杂问题。这很重要，因为阻力的一个组成部分与船通过产生的波浪辐射的能量有关。由于改进设计所寻求的增益是如此之小，因此用于评估设计的技术必须高度准确；因此，科学研究最小阻力划船/划桨船型的设计必须考虑这些额外的影响，才能得出可靠和现实的结果。目前的建议旨在确定开发一种科学程序的可行性，该程序可用于以现实的方式评估船只的性能，包括不同速度、俯仰和浅水的影响。该程序由三个部分组成：在测试槽中测试模型船体的技术；一种允许对数据进行分析并按比例缩放的技术，以及一种用于数值预测阻力的技术。一个实验装置将被设计、建造并投入使用，这将使一个比例模型的船体形状在一个测试箱中实现真实的运动，包括速度变化和俯仰运动。将对划船的船只进行全尺寸测量；获得的数据将用于检查将测试槽数据按比例缩放到全尺寸的技术。最后，目前正在开发的非定常阻力预测的数值方法将扩展到解决与划船/划桨船体相关的特定问题。如果该方法可行，预计未来的研究将包括对现有设计的评估，以及在现实条件下通过减少阻力来优化船体形状以生产更快的船只。我们还期望对这些复杂流动现象的基本理解能够得到改善，从而在未来更好地预测非定常阻力