THE SIMULATION OF SHIP MOTIONS

A three-dimensional panel method is used to solve the linearized ship motions problem for a ship travelling with steady forward speed through quasi-random incident waves. The exact initial-boundary-value problem is linearized about a uniform flow, and recast as an integral equation using the transient free-surface Green function. This integral equation is discretized in space by using planar panels, on which the potential is assumed to be constant, and in time by using the trapezoid rule. Collocation is performed at the centroids of each panel. A technique for approximating the asymptotics of the solution is presented and use to reduce the required length of the computations. Results are shown for a Wigley hull, with and without a steady forward speed. The calculated hydrodynamic coefficients are compared to experiments, as well as to the calculations of two frequency-domain solutions, and a simulation is performed of the ship travelling through a Pierson- Moskowitz sea.