轴段空心度对舰船复杂推进轴系动力学特性影响分析及多目标优化研究

Effects of Shaft Segment Hollowness on Dynamic Characteristics of Marine Complex Propulsion Shafting and Multi-Objective Optimization

轴系动力学特性直接影响到舰船航行的安全性、隐蔽性和可靠性,为分析清楚轴段空心度对舰船推进轴系动力学特性的影响,以某复杂推进轴系为研究对象,基于有限元法建立其动力学分析模型;采用雷诺方程计算轴承油(水)膜刚度,基于螺旋桨升力线理论近似计算螺旋桨轴承力作为振动激励,研究得到螺旋桨轴、艉轴及中间轴空心度变化对轴系校中及振动特性的影响规律;在此基础上,以各轴段空心度为变量,应用多目标优化算法开展轴系动力学特性综合优化。优化结果表明:轴系前后艉轴承负荷差减小了4.1kN,回旋振动和纵向振动的最大振幅均有所减小,轴系动力学特性得到改善。

The dynamic characteristics of shafting directly affect the safety,concealment and reliability of ship navigation.In order to analyse the influence of shaft segment hollowness on the dynamic characteristics of marine propulsion shafting,taking a marine complex propulsion shafting as the research object,the dynamic analysis model was established based on finite element method.The Reynolds equation was used to calculate the bearing oil(water)film stiffness,and the exciting force of propeller was approximately calculated based on the lifting line theory method as the input of vibration analysis.The influence of hollowness of propeller shaft,stern shaft and intermediate shaft on the alignment and vibration characteristics of shafting was studied and obtained.On this basis,taking the hollowness of each shaft segment as the variables,combined with multi-objective opti-mization algorithm,the comprehensive optimization of shafting dynamic characteristics was carried out.The opti-mization results show that the load difference between front and rear stern bearings of the shafting is reduced by 4.1kN,the maximum amplitude of whirling vibration and longitudinal vibration is reduced,thus the dynamic characteristics of shafting are improved.