基于动力吸振器的潜艇推进轴系轴向减振研究

Design of dynamic vibration absorbers to reduce axial vibration of propelling shafts of submarines

螺旋桨脉动推力经推进轴、推力轴承及其基座传递到壳体,是潜艇壳体产生低频轴向振动与声辐射的一个重要因素。本文基于四端参数法建立了综合考虑推进轴系和壳体弹性的潜艇轴向振动力学模型,以轴系传递到壳体的纵振功率流为评价指标研究了轴系的轴向振动传递特性,详细讨论了用动力吸振器实现轴系轴向减振的设计方法。研究结果表明,螺旋桨脉动推力会在轴系各阶纵振频率附近频段激励起轴壳耦合的轴向共振,显著增加轴系到壳体的能量传递。用动力吸振器可以有效抑制轴系各阶轴向共振频率附近的轴-壳共振,而对其它频段的轴壳轴向共振则效果不佳。

Excitation of the longitudinal modes of hull by the fluctuating thrust from propeller-shafting system is a major source of the radiated noise at low frequencies of submarines.Based on the four-pole parameters method,a simple model for analyzing the axial vibration of submarines was proposed,which takes account of the elasticity of the hull,thrust bearing and shafts.The axial transmission of powerflow from shafting to the hull was investigated.It is found that the fluctuating thrust will induce resonances of the shafting and its elastic coupling with hull will result in powerflow peaks.Such resonances are more significant while their frequencies are around the axial modes of the shafting.Dynamic vibration absorbers were designed to depress such powerflow peaks.It is found that absorbers can reduce the powerflow more effectively when they are tuned to resonances around the axial modes of shafting than tuned to others.