Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/1838
標題: 划槳與搖櫓之推進力學
Propulsion Mechanics of Rowing and Yulohing
作者: 楊承桓
Yang, Cheng-Huan
關鍵字: Yulohing;搖櫓;Rowing;Propulsion;划槳;推進力學
出版社: 機械工程學系
摘要: 
人力船隻推進工具對人類發展史具有重大影響,而其推進效率的高低更常影響國家興亡,朝代更迭,甚而改寫人類歷史,對近代船舶之推進方式也有重大開啟先河的歷史性意義!然而傳統的計算流體力學因受限於流力公式本身先天性之問題,常會導致計算結果的嚴重誤差,故本文仍以流力實驗值為重要參考依據。本文首先探討由於不經意地假設無能損條件下,流力基本動量分析理論體系推導過程的歷史性重大失誤。其次說明傳統固定式與滑動式座椅划槳的作動情形與滑動式必然勝出之原因,再由阻力與動量守恆的觀點,且融合先進火箭理論來探討划槳的能量分配與船身推進力。第三,詳細分析搖櫓各式方法的作動情形、優缺點與可獲高推進力之相關原因,且參考槳葉大小、船隻推進器演化、現代飛行器、多種生物推進方式與魚類推進的演化過程,以探討划槳與搖櫓之推進力學與控制技巧,如此必將有助於河海及空中交通載具推進效率的提昇。本文並發現看似平淡無奇的搖櫓,因其能在運作過程中擷取流體的能量,而逐漸演化成現代最先進的船舶螺槳推進器,事實上這也只不過是搖櫓的旋轉形式而已,搖櫓則可視為螺槳的往復形式!因此綜觀魚類推進的演化、與人力推進器的發展,再回顧此一中國先民的智慧,只有令人擊節讚賞不已!

Propulsive tools of man-powered ships have a considerable effect on the history of human development. The efficiency of these tools can even determine the fates of nations, dynastic changes, and even rewrite the history of human beings. Historically, these tools are predecessors of modern ship propulsion! However, the traditional CFD suffered some intrinsic problems in its fluid dynamics equations often resulting in serious inaccuracies. So, in this paper, we still rely heavily on experiment results of fluid dynamics as important references. First we demonstrate that some historical serious derivation errors in the momentum equations of fluid dynamics are due to a careless assumption of no-energy-loss condition. Secondly, we describe the motion of the traditional fixed stroke and the sliding stroke of rowing ships, and explain the reason why the latter would stand out. Then we discuss the energy distribution of rowing and the propulsive force for the hull from the view of drag and momentum conservation, with the aid of advanced rocket theorems. Then, we analyze the motions of yulohing, its advantages/drawbacks, and the reasons why it can provide high propulsive force. Also, in hope to enhance the propulsion efficiency of air/sea vehicles, we study the propulsion mechanics and control technique of rowing and yulohing, in reference to size of paddles, the evolutions of ship propulsion, the modern aircraft, and the propulsive method of various creatures including fish. In this paper, we also find that the yuloh, as a predecessor, eventually evolves to become the most advanced modern screw propeller due to its feature of drawing energy from flow. In fact, the modern screw propeller is just the rotating form of ancient yulohing, and reversely yulohing can be regarded as the reciprocating form of screw propeller! So, while making a comprehensive survey of the evolution of fish propulsion, and the man-powered ship propulsion, we cannot help but amazingly applaud for these ancient Chinese wisdom of yulohing.
URI: http://hdl.handle.net/11455/1838
Appears in Collections:機械工程學系所

Show full item record
 

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.