非定常机匣处理对失速先兆波的抑制作用实验研究

非定常机匣处理在不影响效率的前提下可以明显提高压气机的稳定工作范围,针对这种通过改变斜槽和气室来调节壁面阻抗边界条件的新型处理机匣,从非定常角度,开展其对失速先兆波产生及发展的影响的实验研究.在压气机转子前缘附近沿圆周均匀布置八支高频响压力传感器,采集壁面动态压力信号,进行周向傅立叶分析(SFT)和功率谱密度分析(PSD),捕捉到旋转失速先兆波的出现和发展的动态细节,比较光壁和处理机匣两种情况的结果,证实了处理机匣并非阻止了失速先兆波的出现,而是有效的抑制了其非线性发展.非定常机匣处理改变了压气机系统的阻抗边界条件,能够在全过程中对低频扰动波进行有效的抑制,从而推迟旋转失速的发生,实现压气机的扩稳目的. 

An experimental study on inhibition of unsteady casing treatment on stall inception

A kind of unsteady casing treatment was used to enhance the stall margin of an axial flow fan,which did not result in any recognizable efficiency loss.So,it is quite important to understand the mechanism of stall margin improvement with such casing treatment.The present investigation firstly developed a technical method for measuring and analyzing the inception wave,and then made some detailed comparisons with the existing results.The experimental results show that the unsteady casing treatment will delay the non-liner development of stall process by suppressing the propagation of inception wave in comparison to the evolution of the inception wave without casing treatments,while the inception point will not be changed with the application of the unsteady casing treatment.