基于动刚度法的水面船舶桨-轴-船体耦合系统

Propeller-Shaft-Hull Coupling System of Surface ShipBased on Dynamic Stiffness Method

为分析在低频段内船体两侧螺旋桨激励相位差对船体振动的影响,基于动刚度法建立水面船舶桨-轴-船体耦合系统的横向振动3梁耦合模型。将动刚度法的计算结果与有限元法进行对比,表明动刚度法具有良好的精度。分析桨-轴-船体耦合系统的垂向固有振动特性。在低频段内该系统主要表现为船体梁的振动,推进轴系对船体梁的固有特性影响较小。对左右双桨分别施加不同相位差的单位垂向简谐力,计算由各轴承位置输入至船体梁的功率流。结果表明,双桨激励相位差的增大会使输入至船体梁的功率流变小。因此,在对桨-轴-船体耦合系统的横向振动控制方面,应重点关注双桨激励相位差较大时的工况。

In order to analyze the influence of phase difference of propeller excitation on both sides of hull in low frequency band on the hull vibration,a transverse vibration three-beam coupling model of propeller-shaft-hull coupling system of surface ship is established based on the dynamic stiffness method.The results of the dynamic stiffness method are compared with those of the finite element method,which shows that the dynamic stiffness method is of good accuracy.The vertical natural vibration characteristics of propeller-shaft-hull coupling system are analyzed.In low frequency,the system mainly reflects the vibration of hull beam,and the propulsion shafting is of little influence on the natural characteristics of hull beam.The unit vertical harmonic forces with different phase difference are applied to the left and right propeller respectively,and the power flow from each bearing position into hull beam is calculated.The results show that the power flow into hull beam decreases with the increase of double-propeller excitation phase difference.Therefore,in the transverse vibration control of propeller-shaft-ship coupling system,it is necessary to pay more attention to the working condition when the double-propeller excitation phase difference is large.