权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Study on Propulsive Performance of Marine Animal in Swimming Motion

海洋动物游泳运动推进性能研究

基本信息

批准号：
63550329
负责人：
HIRANO Susumu
金额：
$ 1.34万
依托单位：
Osaka Prefecture University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1990
项目状态：
已结题

项目摘要

There are the data that swimming speed of dolphin may be proportional to their body length (L). Low resistance, high propulsive efficiency or high muscle power has been realized.The objective of the study is to determine experimentally with a model what swimming movements a dolphin can make which will give it high propulsive efficiency. This study is composed of three steps ; that is, the 1st step is to investigate swimming movements of real dolphin ; the 2nd step is to make a model ; the 3rd step is to make experiment with the model. At the 1st step, back stroke swimming movements of a dolphin were recorded and analyzed. From the results, it has shown that its movements are repetition of hogging and sugging, and looks like 2-node beam vibration, that is, its movemets belong to standing wave form.Sir J. Lighthill were concluded theoretically as follows. For marine animals wishing to propel themselves efficiently and to attain high speed through water, it is necessary to pass a raveling wave beneath the body. But efficiency of the standing wave form here observed cannot exceed 50%. To clarify whether the standing wave form is efficient or not, a model which moves by standing wave form has been made.For rigidly constructed model, there are problems on the strength of its body. Then, in this study, the elastic body construction was adopted, namely, piano-wires were employed for longitudinal strength member. The model length was 0.3m (1/10 scale). Size of piano-wire has decided in consideration of the law of similitude.Both resistance tests and swimming tests were carried out in the towing tank. In the swimming tests, the maximum speed was 0.5m/sec.

有数据表明，海豚的游泳速度可能与其体长成正比(L)。低阻力、高推进效率或高肌肉力量已经实现。本研究的目的是通过实验模型来确定海豚可以做出什么样的游泳动作，从而使它的推进效率更高。本研究由三个步骤组成，即第一步是观察真实海豚的游泳动作；第二步是制作模型；第三步是用模型进行实验。在第一步，记录和分析了一只海豚的仰泳动作。结果表明，它的运动是重复的贪婪和暗示，看起来像是2节点梁的振动，即它的运动属于驻波形式。对于希望在水中高效推进并获得高速运动的海洋动物来说，有必要在身体下面通过一个松散的波浪。但这里观测到的驻波效率不能超过50%。为了弄清驻波形式是否有效，制作了一个以驻波形式运动的模型，对于刚性构造的模型，存在其身体强度的问题。然后，本研究采用弹性体结构，即纵向受力构件采用钢丝绳。模型长度为0.3m(1/10比例尺)。根据相似规律确定了钢丝绳的尺寸，在拖曳水池中进行了阻力试验和游泳试验。在游泳测试中，最大速度为0.5米/秒。