![Sample our Engineering & Technology journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5933/TOC-Subject-Sample-2021-Engineering-Tech.jpg"})
Abstract
The controllable flaps and interceptors in planing crafts not only may reduce the resistance, but also could be designed to make a boat run at or near optimum attitude in various environments, which results in a reduction in both resistance and vertical motion in waves. Planing vessels suffer from porpoising instability and violent vertical motion at high forward speeds. The controllable flaps and interceptors can be used to control and reduce the vertical motion of planing crafts. In the present study, the impact of controlled interceptors on a planing craft seakeeping quality is investigated through application of experimental and theoretical methods. In the experimental part of the study, a scaled-down model of a high-speed planing catamaran is tested with and without controllable stern interceptors in calm water and regular head waves, to investigate the effect of automatically controlled interceptors on vertical motion reduction of the model. Through application of modern optimal control theory and Savitsky's method, a control-oriented model of the vertical motion of the planing boat with interceptors in calm water and waves is developed. A simulation environment has been developed in MATLAB and SIMULINK. MATLAB has been used to formulate the model and to provide a suitable environment for control studies. The results obtained, the model, shows good agreement between the experimental and simulated data. Both the experimental and simulated results show that controllable aft interceptors can be used not only for minimising resistance, but also for reducing the vertical motions, especially at or near the resonant frequency. The results also proved that in automatic control system for controlling stern interceptors, a feedback of pitch angle and pitch velocity to the interceptors are effective for vertical motion damping of planing boat in calm water and head waves.