低速轴流压气机三维流场测量与失速特性分析

Three-dimensional Flow Field Measurement and Stall Characteristic of Low-speed Axial Compressor

在近失速和失速状态下,利用五孔探针对单级轴流压气机转子前后的三维流场进行了详细的测量和对比分析。基于失速状态下进出口壁面静压的动态变化,对失速区的空间结构和气流参数的动态变化规律进行了研究,建立了描述失速区气流参数变化的微分方程模型,并根据实验数据对模型进行了校验。结果表明,失速区内发生了回流,回流的速度方向与主流的夹角约为110°。回流区占据的径向范围为70%叶高以上,轴向范围为静子前部区域。在失速区内,压力、速度等气流参数随时间进行振荡衰减。该动态变化过程可以用二阶系统来描述。

The three-dimensional flow fields both in front and at the back of the rotor of a low-speed axial compressor are measured in detail and the contrastive analysis is performed in a state of approximative stall and stall by utilizing a five-hole probe. Based on the dynamic variable curve of the static pressure on the surfaces of the casing in the entrance and the exit under the condition of a stall state, the spatial structure of the stall region and the dynamic characteristic of flow parameters are researched, a differential equation model is established to describe the dynamic process of the airstream in a stall state, and the model is also validated by the experimental data. The results show that the backflow happens in the stall region, the in- cluded angle between the backflow speed and the partial airstream in direction is 110°. The radial scope oc- cupied by the backflow region exceeds the blade tip region by 70%, and the axial scope is the span in front of the stator. The flow parameters, such as pressure and velocity etc., fluctuate damply with time in the stall region, and the dynamic variable process can be described by a two-order system.