臺灣大學: 土木工程學研究所蔡丁貴簡郁桓Jian, Yu-HuanYu-HuanJian2013-04-012018-07-092013-04-012018-07-092012http://ntur.lib.ntu.edu.tw//handle/246246/255522本研究以階形波(step wave)之前進波模擬均勻流(uniform flow)流況，將階形波展開成傅立葉級數(Fourier series)而形成一組單頻進行波受等水深中直立圓柱互制之解析解，從勢流(potential flow)線性理論的觀點，嘗試求得均勻流受到圓柱繞射之問題的三維近似解析解。 本文將以所求得之解析解簡化在長波理論近似下，與現有之二維平面均勻流流經圓形之速度勢及流場之解析解結果進行比較，以驗證本研究之正確性。本研究最終目標是期望能以三維近似解析解的方式求得均勻流受到直立圓柱繞射之問題的水位變化量，但此目標目前仍無法達成，在本文的最後將整理出所遇到之問題以及可能之突破點。In this study, a progressive step wave is used to simulate the uniform flow condition. Employing Fourier series expansion, the progressive step wave can be approximated by a series of monochromatic progressive waves. Taking advantage of existing theoretical solution of scattered wave field around a vertical cylinder of monochromatic waves and linear potential theory, a three-dimensional approximate analytical solution of uniform flows scattered by a vertical cylinder is presented in this paper. Present approximate analytical can be further seduced for shallow water wave condition and compare with classical theoretical solution of uniform flow passing a circle. Very accurate results are obtained to verify present three-dimensional approximate analytical solutions. However, present approximate analytical approach still can not produce desirable solutions for free-surface displacement. Comments and suggestions are provided in the conclusion for further study.3350269 bytesapplication/pdfen-US勢流理論傅立葉級數均勻流解析解potential flowFourier seriesuniform flowanalytical solutionthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/255522/1/ntu-101-R97521319-1.pdf