Hydrodynamic Yacht Bulb Optimization by Embedding the Hull in a B-Spline Space

A novel optimization method is presented where ship hull geometry is embedded in a B-Spline parallelepiped regardless of the specific approximation of the hull (panels, mesh, surfaces). The optimization procedure deforms the B-spline space while the B-Spline moves smoothly every pre-mapped hull point. Moreover, the final B-spline transformation can be applied on a different geometrical hull approximation to accommodate various hydrodynamic solver input requirements. The paper presents an example where the new method automatically converted a standard bulbous bow of a yacht into an inverted piercing bow. The numerical results for the original bulb were validated with model tests. The bulb performance improvement was evaluated with potential (ν-SHALLO) and viscous flow (STAR-CCM+) solvers, which both show a 9% reduction of the total ship resistance at the design speed. The optimized bow shape can save energy and lower emissions.