垂荡运动下船用旋转机械系统的随机振动特性
Random vibration characteristics of marine rotating machinery systems under heave motion
祝磊磊 1李明1
作者信息
- 1. 西安科技大学 理学院,陕西 西安 710054
- 折叠
摘要
动力机械作为舰船心脏,其安全稳定运行对航行安全影响极大,而船舶在航行时受到的牵连运动会对船用旋转机械系统的振动产生重要影响,因此研究垂荡作用下的船用旋转机械的动力学特性及其振动控制具有重要的理论及工程意义.为了研究船用旋转机械耦合气囊浮筏系统在垂荡运动以及噪声激励共同作用下的非线性随机振动特性,首先,将气囊模化为三次非线性弹簧和线性阻尼器,旋转机械和浮筏之间简化为线性弹簧和线性阻尼器;然后,引入了高斯白噪声作为随机激励,建立了系统在垂荡运动下的随机动力学模型.最后,采用数值分析方法分析了该系统的随机振动特性,并与确定性系统的仿真结果进行了比较.结果表明:当转子转速较低时,随机系统和确定性系统的振幅相差较小,但随着转速的增加,二者振动幅值相差逐渐增大;当转子处于高转速时,旋转机械与浮筏的质量比对系统振幅的影响较大;除此之外,噪声激励对随机系统动力学特性的影响也随着转子转速的升高而不断增大.研究成果为垂荡运动下船用旋转机械系统的随机振动设计、动力学分析提供了理论依据和分析方法.
Abstract
As the heart of ships,the safe and stable operation of power machinery has a great impact on navigation safety.The implicated motion during navigation can have a significant impact on the vibra-tion of marine rotating machinery systems.Therefore,studying the dynamic characteristics and vibration control of marine rotating machinery under heave motion is of great significance.This paper mainly dis-cussed the nonlinear random vibration characteristics of a marine rotating machinery coupled airbag floating raft system under the combined action of heave motion and noise excitation.The airbag was modeled as a cubic nonlinear spring and a linear damper,and two linear springs and a linear damper were used to connect the rotating machinery and the floating raft.Then,Gaussian White Noise was in-troduced as a random excitation,and a stochastic dynamic model of the system under heave motion was established.Finally,the random vibration characteristics of the system were analyzed using numerical a-nalysis methods and compared with the simulation results of deterministic systems.The results show that:When the rotor speed is low,the amplitude difference between the random system and the deter-ministic system is small,but as the speed increases,the difference in vibration amplitude between the two increases;When the rotor is at high speed,the mass ratio of rotating machinery to floating raft has a greater impact on the amplitude of the system;In addition,the impact of noise excitation on the dynam-ic characteristics of stochastic systems also increases with the increase of rotor speed.The research re-sults provide theoretical basis and analysis methods for the random vibration design and dynamic analy-sis of ship rotating mechanical systems in heave motion.
关键词
垂荡运动/船用旋转机械/气囊/高斯白噪声/随机振动Key words
heave motion/harine rotating machinery/airbag/Gaussian White Noise/random vibration引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据