高速海豚之推進策略分析

外文標題: 
Propulsion Strategy Analysis of High-Speed Dolphin
校院系所: 
中興大學 機械工程學系所
指導教授: 
李興軍
出版年份: 
2008年
主題類別: 
關鍵字: 
摘要: 

學界對海豚的推進策略至今仍未能掌握其精髓。而鯨豚類經過了6千5百萬年演化出高展弦比,輕、薄、窄、高的尾鰭,將大量的水以較小的速度後推,並配合流線形身體曲線,和一身的肌肉作為動力來源,以獲得優異的推進效率,而速度約可達的最高50 公里/小時的驚人速度。本文以創新的「綁架機翼」與「循環馬力」概念,來說明高速海豚如何在韻律式非穏態過程上下搖擺身尾前進時,身體與前肢演化成的偏前胸鰭與尾鰭就如同兩個靈活的可變形機翼,環環相扣以獲得並巧妙地互相利用升力,形成「綁架機翼」現象。進而靈敏地偵測出每段身體的最佳攻角,利用綁架機翼的概念與回歸大海之後約五百萬年演化出的「循環馬力」特殊技巧,擷取升力在升力方向之旋轉功率,以補償大部分抵抗前進阻力的功率,因而大幅提升其推進效率,並輕易地達到驚人的400% 以上,同時也解開了極度困擾學界70多年之Gray悖論的迷惑。

外文摘要: 

Even today academia has not yet been able to grasp the essence of dolphin propulsion strategy. After a 65 million years the cetaceans category evolved a high aspect ratio, light, thin/high tail fin for pushing a large amount of water backward with a small velocity difference in order to achieve a high propulsion efficiency. With streamlined body and muscles as power source basis for propulsion, dolphin can swim up to a maximum speed of about 50 km/hour. Herein we will present the innovative concepts of "kidnapped airfoils" and "circulating horsepower" to illustrate how the high-speed dolphins swim forward with body and tail working like two deformable airfoils tightly linked to utilize their lift forces for each other cleverly to form a "kidnapped airfoils" phenomenon and capture body lift power to compensate most of the body drag power. In this manner the dolphin can greatly enhance its propulsion efficiency to easily exceed 400% or even more, meanwhile it solves the long-plagued perplexity of Gray paradox lasting for more than 70 years.