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论文类型：会议论文
发表时间：2010-01-01
收录刊物：CPCI-S
页面范围：299-305
关键字：harbor resonance; oscillations; Boussinesq model; standing edge waves
摘要：The study of harbor resonance is one of the most classical subjects of coastal hydrodynamics, and a number of research papers and reports have been devoted to addresing various aspects of this problem. Most of these studies focused on the response of the harbor with a constant depth to various incident waves. Evidently, varying water depths exert more or less influence on the resonance of the harbor. In order to get a simple parametric result from the influence of inside water depths on harbor resonance, we extend shallow water equations to the linear, weakly dispersive Boussinesq-type equation by modifying the offshore velocity component, and then use it to investigate possible exciting transverse oscillations in the harbor with a sloping bottom. Thee transverse oscillations are types of standing edge waves, and can be described with the confluent Hypergeometric function. Their resonance frequencies are not only sensitive to the harbor's width but also to the boundary condition at the backwall. Usually, for a fixed width of the harbor and a specific edge mode, the oscillation frequency decreases with the value of d (distance between the backwall and the junction where the extended bottom and mean sea level meet), but increases with the slope s. For a fixed transverse oscillation mode, the higher the edge mode number are, the more energy is distributed in the offshore region. As the reflection at the entrance is induced by the rapid change in geometry plus the effect of different terrain inside and outside, the much higher modes are considered not to stably exist for the limited value of L (length of the harbor).