Analysis of the sea keeping behavior II: Waves of Finite Amplitude

The study of the dynamic behavior of a vehicle moving near the sea surface with waves of finite amplitude is a very difficult task. The assessment of the interaction of a body with a moving boundary of the fluid domain is an unsteady, highly non linear problem. In the present work the above mentioned problem is modeled in the time domain through a boundary integral formulation, and the numerical solution is obtained using a panel method. Some simplifying assumptions are adopted to describe the sea surface and the wake evolution. In order to guarantee a correct definition of the problem and an accurate representation of the wave pattern, keeping the computation effort at a reasonable level, a particular algorithm is built for the solution of the equations system. The model is exploited to investigate the response of the aerodynamic lifting system of the SEA-BUS. To this purpose, the behavior of the wing profiles have been studied varying characteristic parameters of the sea: length and amplitude of the waves. Particular attention has been paid to the analysis of the time histories of the lift coefficient acting on the wing.