中介机匣支柱尾迹效应诱发的高压压气机进口导叶共振现象在多级环境下的数值研究

Numerical Investigation and Optimization on Inlet Guide Vane Resonance of High-Pressure Compressor Caused by Wake Effect of Intermediate Case Strut in Multi-Stage Environment

关键词:  高压压气机  悬臂式导叶  疲劳断裂  中介机匣  支柱尾迹  非定常激振力

Key words:  High-pressure compressor  Cantilever inlet guide vane  Fatigue crack  Intermediate case  Wake effect of strut  Unsteady exciting force

摘要:

为了解决某型燃气轮机高压压气机在进行数个小时试验后出现的悬臂式进口导叶断裂故障，以中介机匣与高压压气机进口级作为研究对象，采用约化方法在故障发生工况下进行了非定常数值模拟，得到了该工况下中介机匣内部的流场演化情况与作用在进口导叶叶身上的非定常气动力变化规律，结合叶片模态分析，对引起进口导叶疲劳断裂的原因进行了研究。结果表明：中介机匣支柱的尾迹效应是进口导叶受到周期性激励的主要原因。在故障发生工况下，钝体支柱流动尾迹的周期性激励频率与叶片自身一阶固有频率接近，导致高压压气机进口导叶产生共振，从而引起了叶片的疲劳断裂。

Abstract:

In order to solve the fracture fault of cantilever inlet guide vane （IGV） in a high-pressure compressor which happened after a few hours of the gas turbine engine test， the intermediate case and inlet stage of high-pressure compressor were selected as the research object， and the reduced method was used for unsteady numerical simulation against the fault occurrence condition. The internal flow field evolution of intermediate case and the change rules of unsteady aerodynamic force acting on the IGV blade were obtained. Combined with the blade modal analysis， the reason of IGV fatigue crack was investigated. The results indicate that the major source of periodic excitation acting on the IGV blade is the wake effect of strut in the intermediate case. At the fault occurrence condition， the frequency of periodic excitation formed by the flow wake of blunt strut is close to the 1st natural frequency of IGV blade， which leads to the resonance of IGV blade and causes the fatigue crack.