Wave forces on three-dimensional floating bodies with small forward speed.

摘要

A boundary integral method is developed for computing first-order and mean second-order wave forces on floating bodies with small forward speed in three dimensions. The method is based on applying Green's theorem and linearizing the Green function and velocity potential in the forward speed. The velocity potential on the wetted body surface is then given as the solution of two sets of integral equations with unknowns only on the body. The equations contain no waterline integral, and the free surface integral decays rapidly. The Timman-Newman symmetry relations for the added mass and damping are extended to the case when the double-body flow around the body is included in the free surface condition. The linear wave exciting forces are found both by pressure integration and by a generalized far-field form of the Haskind relations. The mean drift force is found by far-field analysis. All the derivations are made for an arbitrary wave heading. A boundary element program utilizing the new method has been developed. Numerical results and convergence tests are presented for several body geometries. It is found that interference phenomena may lead to negative wave drift damping for bodies of complicated shape. 13 refs., 24 figs.