MODEL EXPERIMENT ABOUT RESPONSE OF FLOATING ICE SHEET SUBJECTED TO MOVING AIR CUSHION VEHICLE

According to the differential equation of thin elastic vibrating plate and the similarity theory, the similar relationships of corresponding parameters were determined between model and prototype about floating ice sheet subjected to moving air cushion vehicle (ACV). The calculation formulas of phase speed and group speed about wave propagation of floating ice sheet with free vibration were derived, and the minimum phase speed and propagation speed of shallow wave were as the first and the second critical speed of ACV, respectively. A high accuracy non-contact laser system was developed to measure the surface displacement, and a series of experiments were carried out about response of film deformation causing by air cushion load (ACL) moving at different speeds in towing channel with variable depth. The existence of critical speeds of ACL which could bring maximum film deformation was confirmed. The first critical speed made maximum depression deformation of film after ACL, and the second critical speed made maximum raised deformation of film before ACL. The influence of moving air cushion speed, height, pressure and water depth on film deformation and critical speeds was further analyzed by experimental results; the resonant effect of energy accumulation and mechanism of amplification about film deformation caused by moving ACL were revealed, and the research provides the theoretical basis and technical support to develop a efficient ice-breaking way by ACV.