Wave-Induced Local Steady Forces on a Column-Supported Very Large Floating Structure

摘要

An accurate numerical calculation method is presented for the wave-induced steady forces and moments on each of the columns supporting a very large floating structure. The method is based on the direct integration of the pressure over the wetted surface of each column. First-order quantities needed in computing the pressure are determined by applying a higher-order boundary element method combined with the wave-interaction theory taking account of hydrodynamic interactions exactly within the linearized potential theory. The effects of motions of a structure are incorporated consistently up to second-order in the wave amplitude. Experiments in head waves are also conducted using 64 truncated vertical cylinders arranged in a periodic array of 4 rows and 16 columns. Steady wave forces are measured at 6 different positions among 64 cylinders, and they are all in good agreement with computed results. Some characteristics in the variation tendency of the local steady forces are summarized.