High-Speed Craft with Double Interceptor System in Calm Water: URANS Solution

Interceptor is a high-lifting device used in high-speed crafts to correct trim angle and, to some extent, reduce hull resistance. Double Interceptors System (DIS) is an unconventional configuration that involves two interceptors, one is installed on the transom and the other in the middle of the hull length. This design can lead to a higher reduction in drag and trim angle, though designing and implementing efficient DIS requires a thorough understanding of its hydrodynamic performance. This study uses the SIEMENS PLM StarCCM+ code to numerically simulate high-speed craft with and without DIS in calm water and presents the effects of DIS on hull trim angle, drag, and pressure distribution on the hull bottom. Furthermore, the effects of different interceptor heights on its efficiency have been investigated. The accuracy of the current models is examined by comparing the measured trim angle and drag against the experimental results of towing tank tests provided by De Luca and Pensa, (2012a). The obtained results revealed that using DIS causes an unwetted surface area behind the forward interceptor, consequently reducing the wetted surface area and shear drag. Moreover, a high-pressure region appears when the water flow encounters the interceptor, which can affect the pressure drag. As this high pressure does not lead to a rise in total drag, it can improve lift force distribution and longitudinal stability.