A study on hydrodynamics of the air cushion of a high-speed PACSCAT

This paper presents an approximate but efficient method for modeling the hydrodynamics and seakeeping performance of partial air cushion supported catamaran (PACSCAT) with planing demihulls. This method takes into account of the effects of the waves on the air-water interface under the air cushion induced by the pulsating pressure in the cushion and by the demihulls, which are ignored by existing approximate methods. Specifically, the new developments are made in two aspects. One is that the governing equations of the heave and pitch motions of the PACSCAT are derived to include the effects of the waves under the air cushion due to the pulsating pressure and the demihulls. Another one is that an approximate method is developed for evaluating the waves due to the pulsating pressure. Better agreement between the experimental data and the numerical results for pressure is achieved.