Basic Design and Virtual Prototyping of a Hydrofoil Hybrid Daysailer

The paper presents a preliminary design activity and virtual prototyping of an innovative boat equipped with hydrofoils and hybrid propulsion, with the aim of extending the foil technology from the field of competition boats to recreational day-cruiser yachts and creating a craft with minimal environmental impact. Hydrofoils allow boats to rise from the water, greatly reducing resistance and increasing performance. The current work dealt with the preliminary design of a daysailer with foil technology and hybrid propulsion that allow to combine green and comfortable navigation both under sail and motor and that, when required, can sail in a more performing way by exploiting the foil technology and the thrust of the wind. After having deepened the theory and physics of sailing on foils, a MATLAB code was created to integrate the stability equations that characterize hydrofoil sailboats: connecting the acting forces and allowing to define the dimensions of the geometries, the code was fundamental in speeding up the iterative preliminary design process. The next step was to model the geometry of the hull and the appendages in the CAD environment and, subsequently, the wing movement mechanism so that it could both manage the incidence of the wings and retract the foils when the boat is moored. The hull, profiles, and wings were subsequently placed in a CFD and VPP virtual environment for testing their resistance. Future developments will include a detailed design and the physical prototyping of a first boat for water testing.