Response Reduction of Motion and Steady Wave Drifting Forces of Floating Bodies Supported by Aircushions in Regular Waves

This paper describes the response characteristics and reduction effect of motion and tether tension of two test models that float in water waves by using buoyancy of aircushions. The experimental basic model is 3m long. The basic model has a large mono-aircushion. The second model has three aircushions. Objectives of this study are to examine responses of vertical motion and the wave drifting force and to prove that aircushion supporting system is available in order to reduce vertical motion and the wave drifting force simultaneously using model experiments in a wave tank. Motion response and tether tension of a linear spring are measured. Not only linear responses of them but also steady responses due to the wave drifting force are measured and analyzed. The result of the model tests has proved that draft of skirt like walls has much influence to air-pressure in the aircushion and motion response when the mono-aircushion is compartmentalized to three aircushions. It is found that nonlinearity of response of the air-pressure is strong. Finally we can confirm that reduction of vertical motion and the wave drifting force simultaneously is possible experimentally.