碩士 / 國立清華大學 / 動力機械工程學系 / 95 / The objective of this study is to investigate how can blood parrot cichlid perform highly efficient and maneuverable swimming locomotion in the water and to design a biomimetic fin which is consistent with the dynamic performance of the caudal fin of blood parrot cichlid. The comparison of propulsive performance between deformable and rigid fins is a main part of this study. Besides, the experiments are carried out using both living fish and artificial mechanism mimicking fish tai and a new experimental technique, stereoscopic digital particle image velocimetry (SDPIV), is manipulated to do quantitative analysis. At last we compare the topology flow structure between caudal fin of blood parrot cichlid and the best performance artificial fin. The qualitative flow visualization of caudal fin shows that there are three locomotion types of caudal fin maneuvering. (1) pure forward swimming and forward-sinking, (2) pure forward swimming and forward-rising, (3) position holding. The flow field measurement by using PIV shows that vortex pairs were generated by both the dorsal and ventral parts of the caudal fin and the central jet force of the upper vortex ring is larger than that of the lower one during forward-sinking. The flow field of PET fin is more stable and its flow topology is simpler. PET fin can produce larger propulsive force than PVC fin and PET fin maintains its high propulsion efficiency at different oscillation frequency, while the PVC fin can not. PET fin (rectangle, AR=1) has the best performance in propulsion force, efficiency；its flow field has the similarity with flow field induced by the caudal fin. The topological flow field structure induced by blood parrot’s caudal fin and the best performance artificial fin have many similarities. The experimental results show that highly deformable fin have advantages in maneuverability and efficiency.
| Identifer | oai:union.ndltd.org:TW/095NTHU5311035 |
| Date | January 2007 |
| Creators | Kuo, Tzu-Fan, 郭子凡 |
| Contributors | Yang, Jing-Tang, 楊鏡堂 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 129 |
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