An Experimental Approach for the Prediction of Full-scale Forces Acting on the Submerged Control Surfaces of a New WIG Vehicle

摘要

The prediction of the performances of hydrofoils especially forfast vessels, where these foils are employed to control pitch androll motion, is a quite difficult task. Different phenomena haveto be taken into account: fixed and vortex cavitation, relevantfree-surface effect, flow interaction with the strut bearing thehydrofoil. This is the case of the Surface Piercing, HydrofoilControlled Wing-In-Ground Effect (SP-HC-WIG) vehicle: this isa new concept vessel designed to transport payload at cruisingspeeds beyond the limit of conventional high-speed ships. Usinga numerical approach that accounts for all the outlined phenomenais quite complicate and the reliability of the results obtainedis dependent on comparison with experimental data. As a result,an experimental approach to this problem at least in thepreliminary stage of design is still preferred.In this paper we report the results of the experimental campaigncarried out in the frame of the Brite-Euram Seabus-HydaerProject, a research program that aimed to explore the feasibilityof such a vehicle. This test campaign performed at INSEANfocused on the hydrofoils of the Seabus-Hydaer vehicle. By measuringthe forces acting on these submerged control surfaces fordifferent speeds and scales (including also some cavitation tests),tentative values of the forces acting upon the full-scale vehicle atcruise speeds have been issued, overcoming the unavoidable lackof similarity in the performed tests. Different combinations ofconditions were investigated during the tests, in particular differentangles of attack of the control surface and various incomingflow directions. Movies and pictures of the cavitation phenomenaand wave patterns have been taken and analyzed, as a basis tophysically explain the results obtained.