工學院: 應用力學研究所指導教授: 朱錦洲; 張建成龔彥回Kung, Yen-HuiYen-HuiKung2017-03-062018-06-292017-03-062018-06-292016http://ntur.lib.ntu.edu.tw//handle/246246/277002大自然中有許多渦漩能量，像是大氣中為人熟知的颱風、龍捲風，水中泳者擔心的漩渦。根據Kim (2013)反置魚板擺動實驗和文吉 (2016)半圓柱後方魚板擺動實驗，我們結合此二者想法以開發新渦漩擷取能量，故本實驗以鈍角三角柱產生卡門渦街流場，並在後方放置一非撓性自由轉動反置魚板，藉由改變流場流速、魚板長度和魚板與三角柱距離，觀察各種不同變因之現象，並藉由數值模擬來更加了解其現象原因。 前人研究一方面為不同柱體產生之卡門渦街現象觀察，量測不同柱體所得到的阻力係數(Drag coefficient)，一方面為藉由實驗以及數值模擬來研究反置魚板自己因為流場而引發的擺動。我們將反置魚板置於三角柱後方，藉由雷射、流場顯影粒子和相機拍攝流場，並用PIV lab觀察並計算各流場資訊，以推測各實驗結果之可能原因，作為之後擷取渦漩能量前置作業。 在不同的魚板長度和流速下，反置魚板會有各種不同的擺動現象，其中長度0.35D的反置魚板在某條件下有我們感興趣之反向雙邊擺動現象。從實驗的流場觀測亦能得知卡門渦街會隨著柱體後方物體改變，當魚板長度越長時所受到的改變越大。 不同的柱體會產生不同之卡門渦街，就此實驗所測試之四柱體，我猜測鳥翼型柱體會是擷取渦漩能量之一大利器。There are lots of vortex energy in the nature, for example, the known tornadoes and the whirlpool scaring swimmer. I want to explore new method of vortex energy harvesting. According to Inverted-flag experiments and the experiment of flapping fish model behind semicircular cylinder, I produce the Karman vortex street by triangular prism and put an inflexible inverted flag which is free-rotating. Change free stream velocity, length of flags and the distance between inverted flag and triangular prism. Then observe and record the results and use numerical analysis to know the reason of the flapping results more. Some of researches are the Karman vortex street of different shapes of column and their Drag coefficient. Some are flapping of the inverted flags. I put inverted flag behind triangular prism and use laser, Polyamide Seeding Particles and camera to get the pictures of flow field. Then figure out the reason of the results by numerical analysis. At different length of flags and velocity, there are several flapping conditions of inverted flag. There is reverse double-side flapping when the length of inverted flag is three and a half times of characteristic length. By observing the flow field of experiment, we know that the flags behind column will affect the Karman vortex street and more seriously when the length of flags is longer. Flow over different shapes of cylinder will occur different forms of Karman vortex street. I think the wing-form cylinder is the best instrument of harvesting vortex energy of four cylinders in this experiment.13304322 bytesapplication/pdf論文公開時間: 2019/8/25論文使用權限: 同意有償授權(權利金給回饋本人)卡門渦街三角柱反置魚板PIV(Particle Image Velocimetry)K?rm?n vortex streettriangular prisminverted flagthesis10.6342/NTU201602588http://ntur.lib.ntu.edu.tw/bitstream/246246/277002/1/ntu-105-R03543063-1.pdf