单盘积油转子系统动力学特性研究

发布时间：2018-07-03 05:57

本文选题：单盘积油转子 + 积油旋转形态　；参考：《大连理工大学》2015年硕士论文

【摘要】：旋转机械是工业中运用最广泛的机械之一,大部分的旋转机械如汽轮机、压缩机、航空发动机等装置内部均有空心腔体结构。由于装置自身密封不良或者存在装配缺陷,转子旋转腔体内常贮存有或泄漏入油液,形成积油转子系统。在某些特定条件下,积油会导致整个转子系统产生强烈的自激振动,一方面会给支撑结构带来较大的载荷力,另一方面,也会使旋转机械腔体产生较大的变形,从而导致转静件碰摩,引起机械结构破坏。因此,研究积油转子动力学特性对于旋转机械的长期稳定运行具有十分重要的意义。本文以单盘积油转子作为研究对象,在流体仿真和实验验证基础之上,获得积油形态变化规律。随后,基于油团力学相似简化和Lagrange方程建立单盘积油转子系统动力学模型。最后,采用数值解析方法,分析了积油转子系统的动力学特性。主要工作包括以下：(1)基于单盘积油转子系统积油盘模型,建立油-盘流体仿真二维模型,采用Gambit网格划分工具,通过网格分块划分方法和边界加密处理,获得油-盘流体仿真结构化网格。(2)采用Fluent仿真软件VOF两相流模型,基于流体静压监测,分析系统偏心、液体类型、积液高度、圆盘转速四个特征参数对积液旋转形态的影响。并通过搭建单盘积油转子系统试验台,验证流体仿真结果。(3)基于油团力学相似性简化,获得单盘积油转子系统五自由度动力学建模方法,进而通过Lagrange方程以及系统动能、势能以及油团阻尼能分析,建立了系统动力学方程。(4)基于数值解析,分析了转子系统在无油团作用下的动力学响应和油团影响下的动力学响应。具体包括转速、积液量和支撑条件对积油转子系统振动响应的影响规律。积油形态研究表明,转轴偏心对积油转子的积油形态影响较大,当系统存在偏心时,积油会出现聚合效应,无偏心时,积油均匀分布于转盘内壁。系统动力学特性研究表明积油的存在对系统振动响应影响明显,积油转子系统中特定的转速、积液量和支撑条件均会激发系统由于积油存在而产生的共振锁频现象,导致系统振动幅值过大,出现异常振动现象。
[Abstract]:Rotating machinery is one of the most widely used machinery in industry. Most rotating machinery such as steam turbines, compressors, aeroengines and other devices have hollow cavity structure. Because of the poor sealing or assembly defect of the device itself, the rotor system is often stored or leaked into the oil system. Under certain special conditions, the accumulation of oil will cause the whole rotor system to produce strong self-excited vibration. On the one hand, it will bring a large load force to the supporting structure, on the other hand, it will also cause a large deformation of the rotating mechanical cavity. This results in rub-impact of rotating static parts and damage of mechanical structure. Therefore, it is very important to study the dynamic characteristics of oil-bearing rotor for the long-term and stable operation of rotating machinery. On the basis of fluid simulation and experimental verification, this paper takes the single disc oil rotor as the research object, and obtains the variation law of oil form. Then, based on the similarity simplification of oil mass mechanics and Lagrange equation, the dynamic model of single disc oil rotor system is established. Finally, the dynamic characteristics of oil-bearing rotor system are analyzed by numerical analysis method. The main works are as follows: (1) based on the single disk oil rotor system oil disk model, a two-dimensional oil-disk fluid simulation model is established, and Gambit mesh generation tool is used to solve the problem. The structured grid of oil-disk fluid simulation is obtained. (2) based on hydrostatic pressure monitoring, the influence of four characteristic parameters, such as system eccentricity, liquid type, liquid height and disk rotational speed, on the rotational configuration of fluid is analyzed by using fluent simulation software VOF two-phase flow model. The results of fluid simulation are verified by setting up a single disc oil rotor system test rig. (3) based on the similarity simplification of oil mass mechanics, the five degree of freedom dynamic modeling method of single disc oil rotor system is obtained, and then the Lagrange equation and the kinetic energy of the system are obtained. Based on the analysis of potential energy and oil mass damping energy, the dynamic equations of the system are established. (4) based on the numerical analysis, the dynamic response of the rotor system under the action of no oil cluster and the dynamic response under the influence of the oil mass are analyzed. The effects of rotational speed, liquid accumulation and supporting conditions on the vibration response of oil-bearing rotor system are discussed. The results show that the eccentricity of rotating shaft has a great influence on the oil accumulation of the rotor. When the system is eccentric, the oil will be polymerized, and the oil will distribute uniformly on the inner wall of the rotary disk without eccentricity. The dynamic characteristics of the system show that the presence of oil has an obvious effect on the vibration response of the system. The specific rotational speed, liquid accumulation and supporting conditions in the oil rotor system can all stimulate the resonance frequency locking phenomenon of the system due to the existence of the oil. The vibration amplitude of the system is too large and abnormal vibration occurs.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH113

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