Experimental and numerical study on the high-speed ship hydrodynamics influenced by an interceptor with varied angle of attack

Efforts to improve the hydrodynamic performance of high-speed ships have been underway for a long time. There are different approaches, one of which is to take advantage of an interceptor. Conventionally, the interceptor blades are mounted vertically on the ship's bottom transom, oriented at a zero-degree angle of attack (AoA). This study comprehensively explores high-speed ships' hulls with and without interceptor configurations, encompassing both negative and positive AoA of the interceptor, conducted through experimental and numerical methods using a fully captive model. The interceptors are strategically positioned and configured. Each configuration was examined under varying AoA settings, with uniform interceptor depths and systematic trim angle adjustments. The Computational Fluid Dynamics (CFD) approach simulates the local flow dynamics around the hull, thoroughly analyzing resistance, pressure distribution, lift force, wave profile, and trim moment. The results indicate that interceptor placement near the keel with AoA adjustments significantly reduces hydrodynamic resistance, while AoA changes have limited impact in other positions. Lift force analysis shows interceptors improve lift compared to the bare hull, but this improvement is not linear across positions. Furthermore, it is observed that adjustments in AoA influence lift, with a negative AoA generally being considered favorable. In summary, carefully considering placement, AoA, and height-to-length ratio is necessary to maximize interceptor advantages.