Fixed and vortex cavitation have a significant impact on performances of hydrofoils especially for fast vessels, where these foils are employed to control pitch and roll motion. This is the case of the SPW-02, the latest configuration of the Surface Piercing, Hydrofoil Controlled Wing-In-Ground Effect vehicle: this is a new concept vessel designed to transport payload at cruising speeds beyond the limit of conventional high-speed ships. In this paper we deal with the measurements of forces acting on the submerged control surfaces of the scaled model of the SPW-02. In particular, we obtained the force coefficients of both the after strut and the control foil at different angles of attack and Reynolds numbers. Movies and pictures of the cavitation phenomena occurring on the submerged foils have been taken and analyzed to obtain information about the grow and collapse of cavities. This paper is based upon the work performed by INSEAN as part of the Seabus-Hydaer Brite Euram Project (Ref. [13]), a research program that aims to explore the feasibility of such a vehicle. In the frame of this program, INSEAN designed and built two models of the struts of Seabus-Hydaer SPW-02, that were tested in the CEIMM (Italian Navy Cavitation Tunnel) hydrodynamic tunnel in Rome.
In recent years, the request of increasing the speed of vehicles has led to new concepts for transporters cruising at speeds beyond the limit of conventional high-speed ships. One of these new configurations is the Surface Piercing, Hydrofoil Controlled Wing-In-Ground Effect vehicle (Ref. [10]). It is basically a large wing operating in ground effect just above the water surface for favorable wing performance (it is known that the ground effect increases the aerodynamic efficiency, i.e. the lift-drag ratio).
