变周期减摇水舱控制与仿真

减摇水舱的设计首先要考虑与船体的适配,同时在设计中要重点考虑水舱的阻尼与周期特性,其中周期特性是水舱最基本的特性参数,适用周期范围越宽,减摇效果越理想。针对变周期减摇水舱的相当长度与一般U型水舱相当长度计算的不同之处——其连通道宽度可调且边舱面积随边舱外壁角变化而变化,通过积分方法推导出了可变周期减摇水舱相当长度的计算公式,提出了一种适用于变周期减摇水舱的估算方法。所设计的变周期减摇水舱采用连通道挡板控制改变周期,避免了气阀控制的时间延迟问题,还可根据船体运动规律调整连通道阻尼挡板以提高减摇效果。以某型船为例,建立了船舶减摇水舱仿真模型。经减摇水舱自由衰减振荡数值仿真方法验证,所提出的周期估算公式可靠。采用该模型研究了变周期减摇水舱的控制方法,结果表明,在其工作范围内,可使横摇角始终保持在8°以内,可以在5.5～18 s的周期范围内有效减摇,大大超过了被动式减摇水舱的工作频带。

Control and Simulation of Variable-Cycle Anti-Rolling Tanks

During the design of marine anti-rolling tanks,the suitability of the tank to the ship should be a priority,and the damping and cycle characteristics should be considered at the same time.Particularly,the tank cycle is a fundamental characteristic parameter：the wider range of application it provides,the su perior stabilized effect is obtained.However,the calculation of the considerable length for variable-cycle anti-rolling tanks is distinct from that for general U type tanks,where the width of water channels for vari able-cycle anti-rolling tanks can be adjusted optionally,and the area of side tanks changes along with the outer corner.In view of the problem,this paper proposed a calculation formula for the considerable length of variable-cycle anti-rolling tanks through the integral approach.The target tank adopted water channel baffle control to change the cycle,which avoids time delay caused by the air valve control,and the optimal stabilized effect could be thus realized by adjusting the damping baffle according to ship motion.To vali date the algorithm,a certain ship model was established with free oscillation numerical simulations con ducted.The results show that the roll angle remains within a range of ±8°,and the roll stabilization is effec tive with a period range of 5.5 s to 18 s,which significantly exceeds the working band of passive anti-roll ing tanks.