A B-spline solver for the forward-speed diffraction problem of a floating body in the time domain

A B-spline based higher-order method is developed to solve the forward-speed diffraction problem of a 3D floating body. The problem is formulated using the transient Green function and a source distribution over the hull surface, and the solution is obtained in the time domain. The source strength and potential distribution over the body surface are represented by open-uniform B-spline basis functions. For the description of the hull surface, however, the open uniform B-spline was found to be inadequate to model a realistic hull surface, necessitating the use of non-uniform B-spline basis functions for the hull surface description. Computations are performed for a Wigley hull, S175 hull and a Series60 hull at different forward speeds. Computed results are validated by comparing them with a wide variety of available results, including 3D numerical computations and experimental results. While many of the existing 3D codes for ship motions require high computing resources, the present method is capable of producing the time simulation results for a very long time using a presently available PC.