Boundary element modeling of multidirectional random wave diffraction by multiple rectangular submarine pits

Abstract

The diffraction of multidirectional random surface waves by one or more rectangular submarine pits is investigated theoretically. The present method is based on the principle of cumulative superposition of diffraction solutions for linear Airy wave theory obtained by a two-dimensional boundary integral equation in water of uniform depth. The constant segment mode has been utilized to obtain the velocity potentials on the interface of each pit, and a specified discrete form of the Mitsuyasu directional spectrum is used for the incident wave conditions. The results of the present model have been validated through the comparison with those obtained by previous works ( kh<1, long wave) for random wave diffraction by single or multiple pits. A further investigation for random wave diffraction has been also studied by considering short wave range kh>1. In accordance with reasonable agreement from these comparisons, it is concluded that the present BEM numerical model may accurately be utilized to predict the wave field around multiple submarine pits or navigation channels in many practical applications.