Numerical Modeling Of Harbor And Several Islands' Wave Field Basing On The Mild-slope Equation

Wave is the most active and important dynamic factors in cosat and offshore engineers, and brings the important environmental load to bear on the coast and marine structure. So it is the great science value and operation significance to study the regularity of wave transforming. In many research methods, the numerical model is one of most ways to solve the wave transformation. To similating the wave field around offshore buildings, for example, single point moorings, artificial island and so on, a numerical model is brought forward considering allied reflection and diffraction of several islands.Basing on the nonatationary linear mild-slope equation developed by Hong Guangwen in 1995, a complete wave model is built considering the bottom friction, nonlinear dispersion relation, and allied reflection and diffraction of several islands. Integrating with corresponding physical and imaginary (open) boundaries, it is solved through Alternating Direction Implicit (ADI) difference method.Several verifications are performed to examine the accuracy of the numerical model at simulating wave refraction, diffraction and reflection on some representative topographies and good agreement has been achieved. Then such a successful model has been applied to simulate the wave transformation considering allied reflection and diffraction of several islands, which can provide consult for design wave parameters of offshore buildings. In addition, wave height is computed in a harbor to judge whether the berth condition is safe enough.