| Summary: | 博士 === 國立臺灣大學 === 工程科學及海洋工程學研究所 === 94 === This dissertation is focused on modeling 3D wave propagation in the ocean coupled with elastic bottom and irregular interface by solving parabolic wave equations. In the past few decades the elastic properties of ocean bottom were usually ignored to simplify problems by assuming a fluid seabed. Nevertheless, while it is acceptable to make such assumptions in deep water, the effects of shear waves can never be omitted as long as sound waves penetrates into ocean bottom, especially in shallow water where interactions between sound waves and elastic bottom are very frequent. Hence, seabed has to be considered as elastic solids to correctly reveal the propagating behavior of sound waves. Besides, due to the shortness in hardware resources in the past, real 3D problems were often simplified to 2D through axial symmetry assumptions; however a real 3D environment must be taken into consideration especially in shallow water where the assumptions may not valid. In addition, the development of hardware and software is in huge progress so that limitation on computational resources has been gradually released. Under such circumstance, a novel mathematical model and an implicit finite difference method to obtain a numerical solution for predicting wave propagation in a 3D ocean coupled with irregular fluid/solid interface are presented and developed into a computer code C4PM in this dissertation. Theoretical and computational aspects of the proposed parabolic equation solution procedure are investigated. Several numerical examples are included to show satisfactory results after comparing to known reference solutions with shear effects. Finally the directions of future works are proposed which may enhance the model including the application of wide-angle scheme, revaluation of far-field approximation, generation of initial field, generalization to a 3D interface, and energy conserving property of PE model.
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