Author(s): D. H. Zhang; T. L. Yip; A. T. Chwang
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Keywords: Numerical simulation; Mild slope equation; Harbour waves
Abstract: In this paper, a numerical model based on the modified mild slope equation is developed for simulating harbour wave agitation including ship-generated short waves and ocean swells. To simulate ship-generated waves, an oscillating pressure forcing term is introduced into the mild slope equation. Oscillating pressure forces are distributed along fairways in a harbour to simulate the navigation of vast ships and short waves generated. The oscillating pressure force is determined by equating the rate at which the ships transfer energy to the water with the average rate over a period at which the pressure force does work upon the water of finite depth. A set of simultaneous linear algebraic equations for the nodes deduced from the conventional finite element approximation hybridized with an analytical solution is solved by the iterative conjugate-gradient method. The numerical model is validated with the field wave assessment data of Victoria Harbour in Hong Kong, and good agreement is founded. The numerical model can be applied to assess the wave climate of a harbour due to the variations of reclamation, harbour boundary reflectivity, navigation condition and fairways rearrangement.
Year: 2003