TANK SIDE-WALL EFFECT EVALUATED BY USING MULTI-BODY INTERACTION COMPUTATION

摘要

It is well known that hydrodynamic first- and second-order loads measured on ships or offshore structures in wave tanks exhibit large scatter compared to the expected results in open sea, due to wave reflections from the side walls. A number of recent works have given theoretical models for diffraction and radiation solutions including side-wall effects. One way consisting of defining a Green function satisfying the boundary condition on two parallel side walls can yield reliable solutions for a floating body of arbitrary geometry in any position of the tank. Unlike previous studies, we evaluate the side-wall effects by directly using the option of multi-body interaction in usual model of wave diffraction and radiation. The tank side-walls are considered as an independent fixed body. The wave diffraction and radiation around a floating body in tanks is solved by taking into account of interaction between the two bodies. The excellent agreement between numerical results of first-order quantities and experimental measurements validates the present method. It is shown that this direct method is very efficient and can be further applied to the case of two side walls in non-parallel position as well as to take into account of bathymetric variation of sea bottom.