A study of dynamics and periodicals motions of a new hull for yachts, using CFD methods.

In the present study has been investigated using CFD, the dynamic behavior of a yacht’s hull of military origin. The hull, displacement kind, it’s studied to increase the comfort aboard in presence of rolling and pitching. The similarity between the use of the hull for civilian purposes and military purposes comes from the need to have an elevate stability of the platform, to use weapon in the military applications, to have comfort in the civilian ones. The study has been performed using a dynamic mesh with 1 DOF and an UDF. The obtained results have been compared with the ones obtained by the strip theory. The CFD code used to foreseen the results uses also the viscosity of the fluid as variable. To generate the steady wave motion, in the inlet of the control volume has been set a variable mass flow defined by a sinusoidal behavior. The ship, with her own mass and momentum, at each time step , takes a different condition of trim and heel and so a complete remeshing and smoothing of the computational grid are performed as consequence.