A Study of Energy-saving Mechanism in Swimming Fish / 魚類節能游動機制的探討

碩士 / 國立臺灣大學 / 機械工程學研究所 / 98 / The objective of this study is to investigate the swimming maneuvers of a fish. The experiments are carried out using the high speed camera to do motion analysis and particle image velocimetry (PIV) to do quantitative analysis between colored carp swimming in free stream and behind the step. To know how can colored crap change swimming locomotion decreasing energy consumption. The comparison of swimming locomotion and flow field structure between colored crap swimming in free stream and behind the step is a main part of this study.
Colored crap use the propulsion modes of caudal fin and body undulatory motions when swimming in free stream. On the other hand, when swimming behind the step, it use pectoral fins as the main propulsion source to stay. The swimming locomotion analysis shows that the tail-beat frequency is larger than pectoral beat frequency, and the lateral body amplitudes of colored crap swimming in free stream is larger than behind the step. The qualitative flow visualization shows that the production of vortex ring between colored crap swimming in free stream and behind the step is so different. When colored crap swimming in free stream, it choose BCF mode to swim forward. When colored crap swimming behind the step, the direction of the central jet force is different from the central jet of reverse Karman vortex . Besides, we use vortex ring model calculating the value of the central jet force when it swimming behind the step. These values are close to the drag force that it stay in free stream. The experimental results indicate that colored crap know how to manipulate the interaction between the fins and the environmental flow field to decrease the energy consumption when swimming in fast flow.

Identiferoai:union.ndltd.org:TW/098NTU05489181
Date January 2010
CreatorsHsiao-Chen Ho, 何筱晨
ContributorsJing-Tang Yang, 楊鏡堂
Source SetsNational Digital Library of Theses and Dissertations in Taiwan
Languagezh-TW
Detected LanguageEnglish
Type學位論文 ; thesis
Format95

Page generated in 0.0103 seconds