Three-Dimensional Boundary Element Calculation of Directional Wave Generation

• Main Authors: Chia-Jui Wu, 吳佳叡
• Other Authors: Jaw-Fang Lee
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/85803721411096640272

碩士 === 國立成功大學 === 水利及海洋工程學系碩博士班 === 97 === In this study, the problem of directional wave generation in a plane wave basin is solved by using a three-dimensional boundary element method, and evolution of generated waves moving away from the wavemaker, and effects of finite width of wavemaker units are on waves investigated. The three-dimensional boundary element model used is developed based on Laplace equation as the governing equation, and accompanying with free surface, bottom boundary, wavemaker, and lateral boundaries. The lateral boundaries aligned with direction of wave propagation are adopted to avoid wave reflection from the boundaries. The wavemaker boundary is also discretized to describe finite width of each unit of the directional wavemaker. On validation of the numerical simulation, an analytical solution of the problem is used for comparison in which the wavemaker motion is a continuous function. And the comparison indicates that the present numerical model can simulate very well the directional wave generation in the plane wave basin. The present study shows that waves are generated consistent with phase difference of the wavemaker units, and with the distance moving away from the wavemaker boundary the directional waves are eventually evolved. The width of the wavemaker unit also affects the generated wave form. The smaller the width the smoother the evolved wave crest, on the other hand, large width creates obvious discontinuous evolving wave forms. The three-dimensional boundary element method model used in this study can calculate very well the problem of directional wave generation.