高速转子多阶多平面瞬态动平衡方法研究

发布时间：2018-08-29 11:14

【摘要】：转子的动平衡是保证旋转机械正常运行所必须的工艺过程。转子系统的平衡方法,基本属于稳态平衡方法,大多是借助某些特定的平衡识别设备在某几个特定转速下进行平衡的。这类稳态平衡方法不仅费时,而且还不便于现场平衡。为此,研究一种适用于实际发动机转子系统,能准确和高效地识别高速转子不平衡响应的瞬态平衡方法是十分重要的。本文利用高速转子加速起动过程中的振幅响应信息,进行瞬态动平衡方法研究。围绕这一核心内容,提出了高速转子多阶多平面瞬态动平衡方法,建立了变速转子瞬态不平衡响应的高精度仿真算法,通过建立的动力涡轮转子模型分别开展动平衡方法仿真研究及其稳定性和适用性分析。此外,以设计的高速转子起车试验对提出的动平衡方法的有效性和适用性进行验证。论文的主要工作包括:1.高速转子多阶、多平面瞬时动平衡方法将不平衡方位角识别和测点模态比系数应用于高速转子多阶多平衡面动平衡。利用4次加试重加速起车的不平衡振动响应信息,将不平衡试重按照各阶模态共振区进行分解,在多个平衡校面上同时加不平衡试重,从而完成前三阶模态的不平衡校正的瞬态动平衡方法。通过柔性转子和实际动力涡轮转子系统的模拟仿真对提出的平衡方案进行了验证,确立了所建立的瞬时动平衡方法的可行性。2.变速转子瞬时响应的精细积分算法以典型的多盘柔性转子模型为例,推导并建立了基于Magnus级数展开式、适用于变速转子时变运动微分运动方程求解的精细积分法。对所建立的算法开展计算稳定性、积分精度以及计算效率等方面的研究,并与Newmark-β法的结果进行对比分析。在此基础上,以所提出的算法深入分析了柔性转子结构参数瞬态不平衡响应的内在机理,比较了不同算法对不平衡量的识别精度,确定了变速转子精细积分法在瞬时不平衡响应识别上的适用性。3.涡轴发动机动力涡轮转子瞬态响应分析将涡轴发动机动力涡轮转子系统简化为转子—轴承系统,提出合理的简化理论和建模准则,分别用传递矩阵法和有限元法建立适用于瞬时不平衡响应分析的运动微分方程。分析了不同算法得到瞬态响应结果的差异性,在大型旋转机械分析软件Samcef/Rotor中建立涡轴发动机动力涡轮转子系统二维多谐波轴对称模型,利用前三阶临界转速和振型验证了动力涡轮转子模型的准确性。在此基础上分别计算了升速过程中瞬时不平衡响应和突加不平衡响应,总结动力涡轮转子系统瞬时不平衡响应机理。为复杂柔性转子系统的不平衡识别奠定了基础。4.涡轴发动机动力涡轮转子基于起动响应信息的瞬态动平衡依照所提出的平衡方案,结合动力涡轮转子本身的结构特点,研究了不同平衡面在相同条件下动平衡效果。通过研究具有多个分布不平衡质量作用下,不同平衡面组合对平衡效果的影响,确定了前两阶模态平衡的校正面选取。5.动力涡轮转子系统瞬态动平衡方法稳定性和适应性研究研究了动力涡轮转子系统起动过程中受到转速变化、噪声影响和支承非线性等影响因素作用时,对瞬时动平衡方法的平衡精度和平衡效果所产生的影响。总结归纳本文提出的瞬时动平衡方法在高速转子系统中的适用效果。6.动力涡轮转子系统瞬态动平衡试验研究设计了高速旋转器不平衡响应试验的试验方案,测量得到了动力涡轮转子系统基于起动过程的不平衡振动信号。利用跟踪滤波对所采集的非平稳信号进行平滑处理,对比分析了滤波前后响应识别效果。最后利用本文提出的动平衡方法求得动力涡轮转子系统的不平衡识别结果,初步验证所提出的动平衡方法在复杂转子系统中的适用性和有效性。
[Abstract]:The dynamic balance of rotor is a necessary technological process to ensure the normal operation of rotating machinery.The balancing method of rotor system is basically a steady-state balancing method.Most of the balancing methods are carried out by means of certain balancing identification equipment at certain rotating speeds.This kind of steady-state balancing method is not only time-consuming but also inconvenient for on-site balancing. Therefore, it is very important to study a transient balancing method which is suitable for practical engine rotor system and can accurately and efficiently identify the unbalanced response of high speed rotor. A high-precision simulation algorithm for transient unbalance response of a variable speed rotor is established. The dynamic balancing method is simulated and its stability and applicability are analyzed by the dynamic turbine rotor model. In addition, the validity of the proposed dynamic balancing method is verified by the high-speed rotor start-up test. The main work of this paper is as follows: 1. High speed rotor multi-stage, multi-plane instantaneous dynamic balancing method is used to identify the unbalanced azimuth angle and measure point modal ratio coefficient in multi-stage dynamic balancing of high speed rotor. The resonance region is decomposed and the unbalanced test weights are added simultaneously on several balance surfaces to complete the transient dynamic balance method for the first three-order mode unbalance correction. 2. The precise integration algorithm for instantaneous response of variable speed rotor takes the typical multi-disk flexible rotor model as an example, deduces and establishes a precise integration method based on Magnus series expansion, which is suitable for solving differential equations of motion of variable speed rotor in time-varying motion. On this basis, the inherent mechanism of transient unbalance response of flexible rotor structure parameters is deeply analyzed by the proposed algorithm, and the identification accuracy of different algorithms for unbalance is compared, and the appropriateness of variable speed rotor precise integration method for transient unbalance response identification is determined. 3. Turbo-shaft engine power turbine rotor transient response analysis simplifies the turbo-shaft engine power turbine rotor system into rotor-bearing system, puts forward reasonable simplified theory and modeling criteria, establishes the differential equations of motion suitable for transient unbalanced response analysis by transfer matrix method and finite element method respectively. The two-dimensional multi-harmonic axisymmetric model of turboshaft engine power turbine rotor system is established in Samcef/Rotor software. The accuracy of the dynamic turbine rotor model is verified by the first three-order critical speed and mode shapes. The mechanism of transient unbalance response of power turbine rotor system is summarized based on unbalance response and sudden unbalance response, which lays a foundation for unbalance identification of complex flexible rotor system. The effect of different balancing planes on dynamic balancing under the same conditions is studied. The influence of different combinations of balancing planes on balancing effect is studied under the action of multiple distributed unbalanced masses. The selection of correcting planes for the first two order modal balancing is determined. 5. The stability and adaptability of transient dynamic balancing method for power turbine rotor system are studied. This paper studies the influence of speed variation, noise and support nonlinearity on the balancing accuracy and effect of the instantaneous dynamic balancing method in the starting process of a power turbine rotor system. The unbalanced vibration signals of the power turbine rotor system based on the starting process are measured. The non-stationary signals collected are smoothed by tracking filter, and the identification results before and after filtering are compared and analyzed. Then the unbalance identification results of the power turbine rotor system are obtained by using the dynamic balance method proposed in this paper, and the applicability and effectiveness of the proposed dynamic balance method in complex rotor system are preliminarily verified.
【学位授予单位】：西北工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TK401

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