【作者】 缪辉；

【导师】 王克明；

【作者基本信息】 沈阳航空航天大学 ， 航空宇航推进理论与工程， 2012， 硕士

【摘要】 航空发动机转子系统的动力学特性决定着航空发动机工作的可靠性和结构的完整性,因此对航空发动机转子系统的动力学特性进行计算和分析具有重要意义。本文采用有限元方法对一个简单的双转子系统模型的动力学特性进行了计算,分别采用三种有限元建模方法对其进行计算和分析,验证三种建模方法的可行性和计算方法的正确性,从而为某型航空发动机转子系统的合理建模和计算奠定了基础。合理地建立发动机转子系统的有限元模型对研究发动机整机振动具有重要意义。本文采用四种有限元建模方法对具有弯扭叶片的转子系统的临界转速进行了计算。通过对计算结果分析发现,叶片简化为质量单元的三维模型和具有弯扭叶片的三维模型的计算结果的误差很小,由此提出了对航空发动机轴和轮盘采用三维模型,叶片采用质量单元的建模方法进行建模,有效兼顾了模型的规模与计算的精度。本文提出了对某型航空发动机转子系统建模的方法并对其进行合理建模。在进行临界转速计算之前,首先计算了该发动机支承系统的刚度,然后用APDL语言编制航空发动机双转子系统临界转速的计算程序,用Campbell图法分别得到由低压转子和高压转子为主激励的临界转速和主振型。采用同步响应法分别计算低压转子不平衡和高压转子不平衡引起的响应,得到高、低压转子上各个盘的位移频率响应曲线,同时还得到了高、低压转子为主激励的临界转速,最后对这两种有限元方法计算得到的临界转速进行相互验证。本文运用有限元的方法对某型航空发动机转子系统的动力学特性进行了计算和分析。结果表明:论文中采取的各种分析方法是可行的,计算结果是合理的,对研究同类航空发动机转子系统的动力学特性具有一定的参考价值。更多还原

【Abstract】 The dynamic characteristics of aviation engine rotor system determine the reliability of operation and the integrity of the structure of an aircraft engine. So calculation and analysis of dynamic characteristics of aircraft engine rotor system are of great significance. In this paper, the dynamic characteristics of a simple dual-rotor model are calculated with the finite element method. Three types of finite element modeling methods are used for calculating and analyzing of the dual-rotor system and the feasibility of these methods is verified, so as to lay a foundation for reasonable modeling and calculating of the rotor system of an aircraft engine.An appropriate finite element model of engine rotor system is important for further studying the vibration of the engine. Four finite element modeling methods are used to calculate the critical speeds of the rotor system with cambered and twisting blades. Through the analysis of the results, it is found that the calculation results of the 3D model with blades simplified to mass element and the 3D model with cambered and twisting blades agree very well. This paper proposes that shaft and disk of the engine are created by 3D model, and the blades simplified by the mass element effectively take account of calculation accuracy and scale of the model.Taking the above mentioned into consideration, this paper proposes a modeling method for the rotor system of an aeroengine,then the model of the system is created reasonably. Before calculating the critical speeds, the stiffness of the support system of the engine is firstly calculated; then the critical speeds of the aeroengine dual-rotor system are calculated using APDL language programs and critical speeds and normal modes excited by the low-pressure rotor and the high-pressure rotor are obtained respectively by Campbell diagram method. The unbalance responses caused by imbalance of the low-pressure rotor and the high-pressure rotor are calculated by synchronization response method, from which the amplitude-frequency response curve of each disk is obtained. At the same time, critical speeds excited by the low-pressure rotor and the high-pressure rotor are obtained. Finally these two types of finite element method are used to mutually verify the critical speeds obtained.In this paper, the dynamic characteristics of the rotor system of an aircraft engine are calculated and analyzed using the finite element method. Analysis results show that the calculation method used in this paper works well and can be used to analyze similar aeroengines. The calculation results are reasonable, which have some reference value for analysis of aeroengine vibration.更多还原