Numerical modeling of nonlinear waves in regional coastal waters

• Main Authors: Chien, Shao-Chin, 簡紹欽
• Other Authors: Tsay Ting-Kuei
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/82865861665453872595

碩士 === 國立臺灣大學 === 土木工程學系 === 86 === Numerical modeling of nonlinear waves in regional coastal waters Shao-Chin Chien Abstract This research is to study the wave deformation under nonlinear effects, and to develop a numerical model of nonlinear waves to describe the wave propagation from deep seas to shallow waters. Based on the results of Wu (1996), a two-dimensional numerical model of nonlinear waves is developed by using finite element method. It can compute the wave field in an irregular region with varying depths. Due to the fact of using perturbation methods, present model provides both linear and nonlinear solutions. To extend applicability of this model, a general sparse method to minimize the computer storage requirement is integrated. It is found that with same computer resource, this model can use more meshes to calculate more precise solutions. Comparisons of present numerical results with experimental data are performed ( Beji & Battjes, 1994; Kittitanasuan, Goda & Shiobara, 1993 ). In weakly nonlinear effects, this model can describe the spatial wave profile and time series wave profile accurately. Computing the wave field around a circular island with paraboloid-varied depths, nonlinear motions of waves with reflection, diffraction and refraction are studied.