An Experimental Study on the Vertical Motion of a High-Speed Planing Craft in Regular Following Waves

It is well known that when a high-speed planing craft travels in following seas it experiences long-periodic motions due to low encounter frequency, and it often loses its course keeping stability. Therefore, it is necessary to study the sea-keeping performance and stability of it in the following seas. In this paper, the vertical motions of a planing craft were measured in following regular waves, and the test results were compared with the theoretical results. In the case of the same encounter frequency, non-dimensionalized motion amplitudes become larger as Froude number is higher, and non-dimensionalized motion amplitudes in head waves are larger than those in follow ing waves. The mean values of the motions in following waves are similar to the running attitudes of a craft in calm water at the same Froude number. ※Keywords: High-speed planing craft(고속 활주선), Regular following waves(선미 규칙파), High-speed towing test(고속 예인 시험), Vertical motion response(연직면 운동응답)