碩士 / 逢甲大學 / 水利工程與資源保育研究所 / 97 / Two-dimensional numerical simulations are performed to study the propulsive performance of fish-like swimming foils using the immersed boundary method. The study of the movement of fishes can be very informative in exploring mechanisms of steady flow control. To validate the numerical method, the flow around a circular cylinder is simulated. The model uses a NACA0012 foil as the profile of the body at an equilibrium position of undulating motion. Simulation of a single fish in the absence of inflow field swimming, and the fish-shaped objects in the fixed-point swing have the inflow field. Observation of these two cases, the fish-shaped tail swing produced by the interaction of vortex structure and efficiency analysis. Then the two fish-shaped objects in the flow field for the internal changes were arranged in tandem and in the side-by-side. Found arranged in tandem cases, be in front of the fish-shaped swing of the vortex generated by the impact of the latter about 20 to 25 percent savings in energy. When distance is more than S / L = 2.5, the energy-saving effect gradually is getting smaller. In the cases of the side-by-side there is almost no energy saving effect.
Through the mathematical equation to create a fish body of three-dimensional model, and use of inlaid oval into two-dimensional fish flat. The main body section is assumed to be elliptical with a major-to-minor axis ratio of 2.2:1, where the major axis corresponds to the height and minor axis corresponds to thickness of the body. However, the tail fin using mathematical equations to express. The top of the fin will be established, in order to minimize the concept of mapping the bottom of the fin. Finally, the fish-shaped body and tail fin combination. In this way, using the mathematical equations to construct three-dimensional geometric fish body can be successful.
| Identifer | oai:union.ndltd.org:TW/097FCU05398008 |
| Date | January 2009 |
| Creators | Wei-ming Lin, 林偉銘 |
| Contributors | none, 廖清標 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 104 |
Page generated in 0.0018 seconds