叶片断裂破坏与气动非定常脉动的关联分析

在离心压气机实际的工况运行中,流量通常在一个区间内变化,如果流量超出稳定工作范围,在叶轮流道中可能会引起旋转失速甚至喘振等非稳定性流动现象,极易引发叶片的疲劳断裂[1].本文基于某型压气机在实际运行中发生叶片叶顶断裂事故,利用CFD软件NUMECA进行数值计算分析,主要从气动方面分析其在各个流量下的流动情况.从非定常流动特征方面深入分析其破坏机理.结果表明在一定的流量下,流场中的压力脉动非常强烈,极有可能引发叶片的疲劳破坏.本研究为压缩机叶片的疲劳破坏机理力学分析提供了可靠的理论依据和坚实的数据基础.

Collaborated Analysis of Blade Failure Mechanism and Unstable Flow of Centrifugal Compressor

In the actual operation of a centrifugal compressor, mass flow rate often changes within a certain range. However, if the mass flow is not within the stable working range, unstable flow, such as the rotating stall or even the surge, may easily cause the fatigue failure of the blades. The blade failure of one compressor in operation was analyzed from the unstable flow feature approach in this paper. Flows of the compressor stage under different mass flow rate were obtained with commercial software NUMECA. Unstable flow features and its effect on the fatigue failure of the blade were investigated. Results indicate that large pressure oscillation may contribute greatly to the fatigue failure of the blade. This analysis may provide a theoretical basis and data foundation for the dynamic analysis of the fatigue failure machanism of the centrifugal compressor blades.