涡流发生器对轴流压气机叶顶流动不稳定性影响的实验研究

Experimental Research on Effects of Vortex Generators on Tip Flow Instability of an Axial Compressor

关键词:  轴流压气机  旋转不稳定性  旋转失速  流动控制  涡流发生器

Key words:  Axial compressor  Rotating instability  Rotating stall  Flow control  Vortex generator

摘要:

为了探究涡流发生器对轴流压气机叶顶流动不稳定性的影响，在一台低速轴流压气机转子上开展了实验研究。将梯形和半球形两种涡流发生器分别安装在转子叶顶上游机匣上，基于不同的安装角度共制定了五种控制方案。分析了气动性能的变化，并采用频谱分析和统计分析方法考察了壁面脉动压力特性的变化。实验结果表明：采用梯形涡流发生器后，除安装角为90°的方案外，其它方案在各工况下扩压能力均略有下降，失速时的流量也明显减小。在流场存在旋转不稳定性或失速的工况，-45°方案时涡流发生器增加了来流的正预旋，增加了气流动量，同时产生的诱导涡会径向迁移，进而抑制了叶顶区域的旋转不稳定性或旋转失速的强度。

Abstract:

To investigate the effects of vortex generators on the tip flow instability of axial compressor， experimental research was conducted on a low-speed axial compressor rotor. The trapezoidal and hemispherical vortex generators were installed upstream of the rotor tip respectively， and five control schemes were proposed based on different stagger angles. The aerodynamic performance was analyzed， and the characteristics of wall fluctuating pressure were studied by means of frequency and statistical analysis. The experimental results show that the pressure rise of the compressor rotor falls off slightly at each operating point and the flow rate at stall decreases obviously after using the trapezoid vortex generators， except for the scheme with 90° stagger angle. At the operating points with rotating instability or stall， the vortex generators with 45° stagger angle increase the pre-swirl of the incoming flow and improve the momentum of the flow， meanwhile the induced vortex propagate radially. These will suppress the strength of the rotating instability and stall in the tip region.