内倾船型的非线性横摇仿真分析

Simulation Analysis of Non-Linear Roll of a Tumblehome Hull Ship

为解决内倾船型的非线性横摇工程分析问题,以内倾船型为对象,基于横摇、纵摇和升沉相互独立的假设,以线性耐波性计算软件预报的响应函数为基础,开发能计入船舶横倾过程中复原力臂的非线性因素对耐波性影响的预报软件,该软件可用于确定不同船型方案的非线性横摇时历曲线。采用该软件完成内倾船型与常规船型之间非线性横摇的差异对比,提出内倾船型在设计中需注意的地方:在设计过程中宜综合考虑内倾幅度与运动之间的影响后再确定内倾程度;采取措施减少内倾船型的纵摇幅值可在一定程度上减少内倾船型的横摇。

In this paper,the nonlinear roll problem for the tumblehome hull is solved. By assuming that nocoupling effects exist between roll,pitch and heave,and that the response functions calculated by the lin-ear sea-keeping software are reliable,a software is developed to estimate the impacts of the nonlinear fac-tor of the righting arm on sea-keeping in a rolling process. Particularly,the time history curves of nonlin-ear rolling effects for different hull projects are calculated,and a comparison is made of the nonlinear rollbetween a tumblehome hull and that of a wallsided hull. Several advices are suggested correspondingly forthe hull design：（a）the effects of the tumblehome amplitude on the motion should be taken into consider-ation during the design process;（b）the restraint on the amplitude of tumblehome hull pitch can somewhatcontrol the amplitude of tumblehome hull roll motion.