Hydrodynamic Analysis of Integrated Interceptor-Stern Flap for Trim Control on High-Speed Planing Vessel

Abstract

In a planing vessel, an interceptor is used to exercise control trim at a limited speed, which can result in excessive drag and bow trim at high speed. Previous studies have combined interceptors with stern flaps to achieve optimal hydrodynamic performance on planing hulls. This study investigated the hydrodynamic characteristics of a planing hull with an integrated interceptor-stern flap. The integrated interceptor-stern flap is a form of integration between the interceptor, which is mounted downwards and vertically on the transom, and the stern flap at the end. At high speed, the same interceptor (i) height converted to an integrated interceptor-stern flap can produce better results. Different flap angles were considered to affect interceptor performance. The fluid flow around the ship model was solved using the Reynolds-Average Navier-Stokes equation and the realizable k-epsilon turbulence model technique. The total number of meshes was determined using mesh independence. In conclusion, while the interceptor showcased significant reductions in resistance and trim across various Froude numbers, its effectiveness was compromised at high speeds due to increased drag and trim height, necessitating caution in its application. Furthermore, integrating stern flaps with the interceptor, particularly with a 5° angle, proved promising in further reducing drag and trim, highlighting the importance of interceptor design considerations for enhancing ship performance.