碩士 / 國立臺灣大學 / 機械工程學研究所 / 101 / In this study, the swimming patterns and energy-saving mechanism in fish school is numerically and experimentally investigated. The fish school phenomenon is first observed and qualitatively studied in experiment. To further investigate the energy-saving mechanism of fish school with mono-factor variable, we quantitatively characterized the wake flow structures, forces, and power consumption using numerical simulation with respect to various swimming patterns.
The results show that the spatial arrangement of school and the shed vortices are highly correlated and significantly affect the performances of the thrusts and power consumption of the fish group. The low pressure suction force produced by the reverse Karman vortices shed by the upstream fish decreases form drag of the downstream fish and facilitates the undulating movement periodically. The head and tail of the downstream fish reveal negative work output at specific time step because of the low pressure region between the downstream fish assisting the body undulation This mechanism reduces the power consumption of each fish in school by 20% averagely compared with that in solo.
In three dimensional simulation self-propelled cases, the results show that the average swimming velocity of the fish following case is greater than that of fish swimming in solo with the same body undulating motion. The energy-saving mechanism reveals in this work offer a physical insight into bio-inspired arrays for the underwater vehicles.
| Identifer | oai:union.ndltd.org:TW/101NTU05489062 |
| Date | January 2013 |
| Creators | Szu-Yung Chen, 陳思詠 |
| Contributors | 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 | 110 |
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