某航空发动机高压压气机盘的振动特性分析

基于含预应力结构模态分析的有限元理论,对某典型航空发动机压气机盘进行振动特性分析。根据初始设计参数,在通用有限元软件中建立起盘的三维有限元模型。首先计算了盘在不旋转时的频率和振型,然后计算了盘在常用转速下存在预应力时的频率和振型,并分析了离心负荷对盘固有振动特性的影响。最后分析了盘的行波振动特性,计算了节径振动的行波频率,考虑盘外缘叶片受到的周期性气体力对盘的激振影响,画出共振特性曲线,为后续结构分析和排故提供依据;同时发现盘的驻波临界转速高于盘的最大工作转速,表明该盘不会发生驻波共振,对保证该发动机的可靠工作具有重要意义。

Vibration Characteristics Analysis of High-Pressure Compressor Disk from an Aero Engine

Based on the finite element theory of pre-stressed modal analysis, vibration characteristic of a typical aero-engine compressor disk had been analyzed. Three-dimensional finite element model of the disk was established in general finite element software according to initial design parameters. First, the natural frequencies and mode shapes of disk was calculated; and then, the frequencies and mode shapes of disk under impact of pre-stress by rotating on common speeds was calculated; also the influence on inherent vibration characteristics of disc for centrifugal loads was analyzed. Finally, traveling-wave vibration characteristics of disk were analyzed, the traveling-wave frequencies of nodal-diameter vibration was calculated. The excitation on disk by periodic air force on the blades which assembly along the outer edge of disk was considered, and the Campbell curve was figured out. It provides a necessary numerical basis for subsequent structural analysis and vibration troubleshooting. Also, the standing-wave critical speed of the disk is greater than the maximum working speed, standing-wave resonance will not happen, it is of great significance to ensure reliability of the aero-engine.