2008-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/691530摘要：本子計畫之目的是要從流體力學及仿生學的觀點切入，研究魚類及蝦類如何能以高效率及高機動性的運動模式在水中自如前進；研究方式將針對生物在流體中的運動行為進行基礎學理研究，首先針對魚類游動之模式 進行歸納探討。魚類游泳時的流體推進效率（Froude efficiency）一般都高於80%，甚至超過90%（Triantafyllou, 2000），屬於極高效率的能量轉換機制，且超過99%之魚類皆是使用有彈性之鰭片，就演化之觀點，彈性鰭 擺動之模態與機制必有優於硬鰭之處，因此彈性鰭與硬鰭之分析比較為本計畫的重點之ㄧ。本研究將以活體魚類及仿魚類擺尾機構進行實驗量測，以結合工程與生物演化之思維，為水中推進機構設計提供一個嶄新的觀 點。另外，魚類可以藉由簡單的擺動魚鰭，穩定的停滯在複雜流況的水域中而不會翻覆或是失去平衡，並迅速藉由胸鰭及尾鰭擺動以整合外界與自身流場，達到平衡的效果，因此魚類之平衡機制也將是研究重點；另外發 現，蝦類對於逃脫的機制有著很好的運用，以生物演化觀點來看，蝦類為躲避魚類之攻擊與掠食，其所發展出來之逃脫機制必定反應得比魚類迅速，所以本子計畫將從流體力學之觀點，研究蝦類甩尾逃脫之原理，並針 對蝦類與魚類運動機制之差異進行分析比較。本研究在實驗方法上，將發展立體粒子影像測速儀（SPIV, Stereoscopic Particle Image Velocimetry，俗稱三維PIV）以用於量測，此技術具有極高的突破性及廣泛應用性，可彌補現有PIV 技術的明顯不足之處，並大幅提升流體力學研究的準確性。<br> Abstract: The goal of this sub-project is to investigate how can fish and shrimp perform highly efficient and maneuverable swimming locomotion in the water. The research will concentrate on the hydrodynamics and kinematics of underwater creatures. In this project, the swimming modes of fish will be examined and classified first. Generally, the fluid propulsion efficiency （or Froude efficiency）of fish is higher than 80%, and even exceeds 90%（Triantafyllou, 2000）, which is considered as an extremely high energy exchange mechanism. In nature, more than 99% of fish have deformable (or elastic) fins. From the viewpoint of evolution, it can be inferred that deformable fins must have advantages over rigid fins. Therefore, the comparison of propulsive performance between deformable and rigid fins is a main part of this project. Besides, the experiments will be carried out using both living fish and artificial mechanism mimicking fish tail. It is believe that the conceptual combination of engineering and biological evolution will provide a brand new way for the innovation of underwater propulsion vehicles. It was often observed that, in extremely unsteady and complex surrounding flow fields, fish can rapidly stabilize itself by simple fin maneuverings. That is, the stabilization is achieved by integrating the surrounding flow and self-generating flow with pectoral and caudal fins. The stabilization functions of fish fins are also one of the key parts of our project. People are often impressed on the abrupt escaping of shrimps. For the purpose of getting away from the attack of preying fish, shrimps have evolved more efficient escaping appendages than that of fish. Therefore, we will also investigate the escaping hydrodynamics of shrimps and compare the difference between fish and shrimps. In this project, a new experimental technique, stereoscopic particle image velocimetry (SPIV), will be developed. SPIV can be used to measure instantaneous three-component fluid velocities on a two dimensional plane. The utilizing of SPIV can greatly enhance the accuracy of flow field measurements and compensate for the defects of traditional PIV.仿生學流體力學推進模式彈性鰭片生物演化平衡模式逃脫機制立體粒子影像測速儀Biomimeticshydrodynamicspropulsiondeformable finsevolutionescapingSPIV