【摘要】 气垫船破冰是指采用大吨位气垫船以临界航速在冰面上航行进行破冰,是一种较新的内河破冰方法,可应用于黄河凌汛灾害的防治领域。对浅水厚冰层条件下气垫船破冰过程进行了数值模拟。计算结果表明:临界航速下,气垫船始终位于船首波峰后方,对所兴起的船波起持续的推波作用,在冰面上逐渐兴起幅值较大的船波。冰层在船尾波谷处最先产生纵向裂缝并向前后延伸,向前延伸至船首波峰处时引起冰层横向破裂并扩展,完成一个破冰周期。船身后方的裂缝沿气垫船轴线方向呈*号形状,不同破冰周期的横向裂缝交叉后,冰层破裂成三角形的碎冰片。气垫船破冰的不同工作航次应尽量沿同一方向平行进行,使不同航次的裂缝进一步交叉,将冰层破裂成尺度更小的碎冰片。更多还原

【Abstract】 A large floating ice sheet can be broken into small slabs with a heavy air cushion vehicle(ACV) traveling on it at a critical speed.Ice-breaking with ACV is a new ice-breaking method in in-land river,it has an important application in prevention of ice jam flood in Yellow River.Here,the ice-breaking process of an ACV was numerically simulated under conditions of shallow water and a thick ice sheet.The simulation results showed that an ACV traveling at a critical speed always chases after the wave crest ahead of it and pushes the waves;thus,the amplitude of the wave around ACV gradually increases due to the continuous push of ACV;initial crack of ice sheet appears at wave trough near the stern of ACV and extends along the axis of ACV in both forward and backward directions;lateral crack at the wave crest ahead of ACV is arisen when the initial crack extends forward to wave crest;an ice-breaking period is finished by ACV accordingly;the cracks behind ACV were shaped as an asterisk symbol along the sailing direction of ACV;the ice sheet breaks into triangular slabs when lateral cracks of different ice-breaking periods intersect with each other;ACV should sail in the same direction parallelly in order to cross the cracks of different ACV voyages and break the ice sheet further.更多还原