WAVE-INDUCED OSCILLATIONS IN HARBORS WITH WAVE-ABSORBING QUAY

Abstract

An artificial wave-absorber (wave-absorbing quay) has come to be widely used to counteract excessive wave action on ships and structures in harbors. Its two-dimensional characteristics on wave absorption have been investigated with several types of the wave-absorbing quay theoretically as well as experimentally, e.g., Jarlan (5), Terret, Osorio and Lean (9), Ijima, Tanaka and Okuzono (3), and Ijima and Okuzono (4), but the effects on the wave reduction in harbors seem to be not fully clear. This may be due to the lack of analytical methods for solving wave-induced oscillations in harbors with the wave-absorbing quay. When the side wall in the harbor basin is assumed to be perfectly reflective, many theoretical methods for solving wave-induced oscillations in harbors have been presented: Ippen and Goda (2) solved the problem of a rectangular harbor by using the Fourier Transform technique. Hwang and Tuck (1) presented powerful method, which is applicable to arbitrary shaped harbors, by using integral equation (source distribution along the boundary) for the expression of the velocity potential. A similar method to that of Hwang and Tuck, but more suitable one for numerical computation, was presented by Lee (6), who used integral equation separately in the harbor basin and in the open sea. Raichlen and Naheer (8), Mattioli (7), and Yoshida and Ijima (10) presented the methods being applicable to the harbors of arbitrary shape and variable depth by further extending Lee's method.