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1.
具有封严蓖齿转子系统的动力稳定性分析   总被引:6,自引:1,他引:5  
封严蓖齿的气弹力对转子系统的稳定性起重要作用,本文建立了具有封严蓖齿的转子系统动力稳定性的分析方法,该方法利用传递矩阵法建立系统的主导方程,将封严蓖齿的气弹力以等效刚度及等效阻尼系数的方式引入转子系统的主导方程,用数值积分法解主导方程,求得系统的动力特性,根据扰动解判断系统的稳定性。本文所建立的分析软件,也可计算转子系统的不平衡响应、临界转速、突加不平衡响应等。文中对一模型转子进行了算例分析。  相似文献   

2.
本文选择了一种可以无限逼近阶跃函数,具有无穷阶连续导数的表示转子突加不平衡的数学模型.用此模型分析了支承在同心型及非同心型挤压油膜阻尼器上的柔性转子的突加不平衡响应.研究了系统参数对突加不平衡响应的影响及不同转速下突加不平衡对系统双稳态响应的影响.证明了设计合理的挤压油膜阻尼器对突加不平衡具有抑制作用.此外,非同心型挤压油膜阻尼器抗突加不平衡的能力要比同心型挤压油膜阻尼器强,但非同心型挤压油膜阻尼器在突加不平衡时容易产生非协调响应.  相似文献   

3.
本文提出了通过逐次将非线性力等效线性化,然后用具有许多优点的 Prohl 法计算等效系统响应的迭代法,用以求非线性转子系统的稳态不平衡响应.实例计算了装有中介轴挤压油膜阻尼器的双转子发动机的稳态不平衡响应.  相似文献   

4.
设计了用于转子振动控制的摩擦板式电流变阻尼器,建立了电流变阻尼器-转子系统的分析模型,根据文献「7」中建立的突加不平衡模型,理论分析了电流变阻尼器抑制转子系统突加不平衡响应,计算分析结果发现:随着外加电压的升高,电流变阻尼器能有效地抑制突加不平衡响应。  相似文献   

5.
航空发动机整机耦合动力学模型及振动分析   总被引:3,自引:0,他引:3  
陈果 《力学学报》2010,42(3):548
面向航空发动机整机振动,建立了航空发动机转子-滚动轴承-机匣耦合动力学模型.该模型具有如下特点:(1)考虑转子、滚动轴承及机匣之间的耦合作用;(2)考虑了实际航空发动机的弹性支承及挤压油膜阻尼效应;(3)将转子考虑为等截面自由欧拉梁模型,运用模态截断法进行分析;(4)考虑了滚动轴承间隙、非线性赫兹接触力以及变柔性VC(Varying compliance)振动;(5)考虑了转子与机匣之间的碰摩故障.运用数值积分方法研究了航空发动机的整机振动规律,包括:滚动轴承VC振动分析、弹性支承刚度对耦合系统临界转速的影响、转轴模态截断阶数NM对系统响应的影响分析、挤压油膜阻尼器参数对系统响应的影响分析、突加不平衡的瞬态响应分析以及转静碰摩故障特性分析等.  相似文献   

6.
齿轮-转子-滑动轴承系统时变非线性动力特性研究   总被引:4,自引:0,他引:4  
本文应用求周期解的数值计算方法─—打靶法和判定周期解稳定性的Floquet乘子研究了齿轮-转子-滑动轴承系统中齿轮啮合时变刚度,滑动轴承非线性特性对转子系统不平衡响应和失稳的影响,并比较了平衡位置失稳和不平衡响应周期解失稳,以及按双轴计算与单轴计算结果的差别,为工程设计理论计算提供基础。  相似文献   

7.
求非线性转子-轴承系统周期响应的一种计算方法   总被引:2,自引:0,他引:2  
本文把求非线性转子-轴承系统瞬态响应的分块Newmark方法与打靶法结合求系统的周期解,该方法利用了分块Newmark方法求解速度快的优点和Jacobi矩阵求解时每步不需迭代的特点。本文首先给出周期解的求解公式,然后用一个算例,讨论了周期解的稳定性及失稳后的分岔行为。  相似文献   

8.
本文使用分析动力学和Bogoliubov-Mitropolskii渐近方法研究位于各向异性支承中的单盘转子在有限能源驱动下通过临界点时的非定常、非线性瞬态响应.通过推导,得到一阶微分方程组,然后数值积分求解.文中讨论了转子盘的陀螺效应,静、动不平衡,内、外阻尼和静不平衡量的初相角等多种因素对瞬态响应的影响.  相似文献   

9.
齿轮—转子—滑动轴承系统时变非线性动力特性研究   总被引:4,自引:0,他引:4  
本文应用求周期解的数值计算方法-打靶法和判定周期解稳定性的Floquet乘子研究了齿轮-转子-滑动轴承系统中齿轮啮合时变刚度,滑动轴承非线性特性对转子系统不平衡响应和失稳的影响,并比较了平衡位置失稳和不平均响应周期解失稳,以及按双轴计算与单轴计算结果的差别,为工程设计理论计算提供基础。  相似文献   

10.
复杂非线性转子—轴承系统动力特性数值分析   总被引:3,自引:0,他引:3  
郑铁生  伍晓红 《力学学报》2001,33(3):377-389
研究非线性高维复杂转子-轴承系统的动力特性。针对系统的局部非线性特征,给出了一种降阶及配套动力积分方法。降阶系统仍保持局部非线性特征,非线性响应数值积分所需的迭代只需在局部非线性的维数上执行。对于油膜力无封闭解的实际轴承,采用变分不等方程有限元法求解Reynolds边值问题,使得油膜力及其Jacobian矩阵的计算变得非常简单明了且与具有协调一致的精度。应用上述方法计算分析了一双跨、椭圆轴承-转子系统的不平衡响应,数值结果展现了系统丰富复杂的非线性现象。  相似文献   

11.
基于Muszynska密封力模型,建立了迷宫密封转子系统的非线性动力学模型,将精细积分法推广应用于非线性情况,计算了迷宫密封不平衡转子系统的动力学特性,依据Floquet理论讨论其分岔特性。研究表明:在2^N类算法计算指数矩阵基础上提出的精细积分法和传统的数值计算方法相比,其精度高,在分析中通过取不同步长计算对比,表明该方法在某些情况下可以采取较大时间步长,有效提高了计算速度。  相似文献   

12.
汽车涡轮增压器广泛采用浮环轴承支承的小型轻质转子系统,以实现100 000~300 000 r/min的工作转速,提高发动机功率和动力性能,并降低燃油消耗和排放. 在此超高速工况下,动压油膜的强非线性作用和转子固有的不平衡效应使该系统呈现出复杂的动力学现象,其中油膜涡动、振荡、跳跃、倍周期分岔和混沌等非线性动力学行为对增压器的健康运转意义重大,因而备受关注. 本文作者从摩擦学动力学耦合的角度出发,基于流体动压轴承润滑理论和有限差分法计算非稳态油膜压力,结合达朗贝尔原理和传递矩阵法建立了转子离散化动力学方程,提出了一种由双油膜浮环支承的涡轮增压器转子系统动力学模型,并从转子轨迹、轴承偏心率、频谱响应、庞加莱映射和分岔特性等方面比较分析,描述了该非线性轴承-转子系统的不平衡效应及油膜失稳特征. 结果表明:转子一般在相对低速下作稳定的单周期不平衡振动,在高转速下其被油膜失稳引起的次同步涡动所抑制,但不平衡量的增加可阻碍转子以拟周期运动通向混沌运动的路径;适当不平衡补偿下,由于内、外油膜间交互的非线性刚度和阻尼作用,在油膜失稳区间之间的中高速区会出现适合增压器健康运转的稳定区间.   相似文献   

13.
In this paper the global response characteristics of a piecewise smooth dynamical system with contact, which is specifically used to describe the rotor/stator rubbing systems, is studied analytically. A method to derive the global response characteristics of the model is proposed by studying each piece of the equations corresponding to different phases of the rotor motion, i.e., the phase without rubbing, the phase with rubbing and the phase of self-excited backward whirl. After solving the typical responses in each phase and deriving the corresponding existence boundaries in the parameter space, an overall picture of the global response characteristics of the model is obtained. As is shown, five types of the coexistences of the different rotor responses and deep insights into the interactive effect of parameters on the dynamic behavior of the model are gained.  相似文献   

14.
In this study, a high-order accurate numerical method is applied and examined for the simulation of the inviscid/viscous cavitating flows by solving the preconditioned multiphase Euler/Navier-Stokes equations on triangle elements. The formulation used here is based on the homogeneous equilibrium model considering the continuity and momentum equations together with the transport equation for the vapor phase with applying appropriate mass transfer terms for calculating the evaporation/condensation of the liquid/vapor phase. The spatial derivative terms in the resulting system of equations are discretized by the nodal discontinuous Galerkin method (NDGM) and an implicit dual-time stepping method is used for the time integration. An artificial viscosity approach is implemented and assessed for capturing the steep discontinuities in the interface between the two phases. The accuracy and robustness of the proposed method in solving the preconditioned multiphase Euler/Navier-Stokes equations are examined by the simulation of different two-dimensional and axisymmetric cavitating flows. A sensitivity study is also performed to examine the effects of different numerical parameters on the accuracy and performance of the solution of the NDGM. Indications are that the solution methodology proposed and applied here is based on the NDGM with the implicit dual-time stepping method and the artificial viscosity approach is accurate and robust for the simulation of the inviscid and viscous cavitating flows.  相似文献   

15.
可倾瓦径向滑动轴承支承的转子系统瞬态响应计算   总被引:3,自引:0,他引:3  
研究了可倾瓦径向滑动轴承支承的转子系统瞬态响应的计算方法,提出了可倾瓦径向滑动轴承非线性滑膜力计算的数据库方法,将可倾瓦与轴颈的结构和运动参数归结到三个参数中,建立了起可倾瓦的非线性油膜力数据库,通过精确插值到每一运动参数组合下轴承提代的油力和轴瓦上所受的油膜力矩。  相似文献   

16.
In this paper, the Riccati transfer matrix method and the component theory of forward and backward whirls are used to the eigenproblem of damped free whirling vibration of a flexible rotor with arbitrarily distributed mass on isotropic or anisotropic supports, with the gyroscopic effect taken into account to find out its critical speeds and corresponding vibrational shape functions. The generalized damped mode theory is developed and extended, which is employed in combination with the Bogoliubov-Mitropolskii asymptotic method to deduce two sets of first order differential equations to calculate the transient response of the rotor with limited power supply passing through its critical speeds in forward whirl and backward whirl respectively. The coupling phenomenon of the rotor through two neighboring critical speeds is also analyzed.  相似文献   

17.
Rotor unbalance and rub-impact are major concerns in rotating machinery. In order to study the dynamic characteristics of these machinery faults, a dual-disc rotor system capable of describing the mechanical vibration resulting from multi-unbalances and multi-fixed-point rub-impact faults is formulated using Euler beam element. The Lankarani–Nikravesh model is used to describe the nonlinear impact forces between discs and casing convex points, and the Coulomb model is applied to simulate the frictional characteristics. To predict the moment of rub-impact happening, a linear interpolation method is carried out in the numerical simulation. The coupling equations are numerically solved using a combination of the linear interpolation method and the Runge–Kutta method. Then, the dynamic behaviours of the rotor system are analysed by the bifurcation diagram, whirl orbit, Poincaré map and spectrum plot. The effects of rotating speed, phase difference of unbalances, convex point of casing and initial clearance on the responses are investigated in detail. The numerical results reveal that a variety of motion types are found, such as periodic, multi-periodic and quasi-periodic motions. Moreover, the energy transfer between the compressor disc and the turbine disc occurs in the multi-fixed-point rubbing faults. Compared with the parameters of the turbine disc, those of the compressor disc can affect the motion of the rotor system more significantly. That is, the responses exhibit simple 1T-periodic motion in the wide range of rotating speed under the conditions of sharp convex point and larger initial clearance. These forms of dynamic characteristics can be effectively used to diagnose the fixed-point rub-impact faults.  相似文献   

18.
In this article, a constitutive theory in the framework of continuum thermomechanics is introduced to represent the viscoplastic behavior of metals at finite deformations. In particular, the experimentally observed thermomechanical coupling phenomena are described by the theory. The model is based on the assumption that the occurring viscoplastic deformations are isochoric.For the numerical integration of the constitutive theory, a backward Euler method is applied. As a matter of fact, the application of the original backward Euler scheme does not preserve the property of the viscoplastic deformations to be isochoric. A major topic of the present article is the development of an improved numerical integrator on the basis of the original backward Euler method, which preserves exactly the incompressibility of the occurring viscoplastic deformations.  相似文献   

19.
非线性系统周期强迫不平衡响应的稳定性分析   总被引:4,自引:0,他引:4  
夏南  孟光 《力学学报》2001,33(1):128-133
多自由度强非线性系统是工程实际中经常遇见的一类模型,利用非线性动力学分析中的打靶法求解该类系统的周期解,并对Flopuet主导特征值判断周期解的失稳方式,利用该方法对旋转机械中的一个具体模型;双盘县臂柔性转子-非同心型挤压油膜阻尼器(SFD)系统周期强迫不平衡响应的稳定性和分岔行为进行了分析,分析表明,在该系统中存在着第二Hopf分岔、倍周期分岔、鞍-结分岔三种分岔形式。  相似文献   

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