A Flow Field Experimental Study on BCF Swimming of Bionic-Flexible Caudal Fin

• Main Authors: Che-Wei Chang, 張哲瑋
• Other Authors: 朱錦洲
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/99931972791476518912

碩士 === 國立臺灣大學 === 應用力學研究所 === 102 === Abstract 　 In this study, we investigate three-dimensional thrust mechanisms of finite rigid and deformable flapping plates experiment as a caudal fin of the BCF (body and/or caudal fin) swimming fish at low Reynold numbers , water propeller vehicles in recent years, many scientist involved in research, and biomimetic water propeller vehicle is popular, with a high from its water propulsion mechanism, both environmental protection, green energy, privacy and so on. The experimental study of the fish BCF swimming field observation, which is characterized by the use of the vortex structure behind it generated vortex propulsion increases with high mobility and operability. Bionic flexible caudal fin is mainly carried out at low Reynolds number, in this case there will be many complex phenomena, such as: reversed-Karman vortex. To simplify the problem, this experiment aspect ratio 1 flapping, using particle imaging, and with the lift and drag measurements. Discuss the development of flexible fin behind and vortex structures. The working fluid is a mixture of experimental glycerol and water, with Reynolds number 500, the number (St=0.2,0.4 and 0.6), and two-way movement. Using the six-axis force compliance record up resistance over time and observe up under a different number St resistance changes with ansys simulation comparison of its results. Flow field observations, with the release of the developer particles to calculate the flow field vorticity with PIV method.