基于叶顶喷气的轴流压气机叶顶泄漏流主动控制

Active Control Study of Tip Leakage Flow in Axial Compressor Based on Tip Injection

为研究压气机叶顶泄漏流对压气机性能影响的流动机理,基于叶顶喷气在小流量工况下对 1 台单级低速轴流压气机叶顶泄漏流进行主动控制。通过喷气前、后非定常数值模拟,对比分析不同轴向喷气偏角下压气机性能提升与动叶叶顶区域流场特性的变化,在叶顶沿弦向布置压力测点,采集叶顶区域不稳定流动的脉动信号,结果表明:轴向、叶顶进气角方向喷气分别获得 5.40%、5.93%的压气机性能提升;轴向喷气能最有效减少通道内的逆流速度团,延缓泄漏流的周向发展;叶顶进气角方向喷气使 50%叶顶轴向弦长处的泄漏流最大泄漏量降低 20%,同时能有效改变泄漏涡发展轨迹,避免撞击到相邻叶片压力面;根据频谱结果发现喷气能够抑制叶顶泄漏流的不稳定性。

In order to study the flow mechanism of the effect of tip leakage flow on compressor performance,the tip leakage flow of a single stage low speed axial compressor was active controlled based on the tip injection at low flow rate. The improvement of the compressor performance and the characteristics of the flow field of the tip region under different axial injection angles were compared and analyzed by numerical simulation of unsteady flow before and after injection. The pressure measurement points of the tip were arranged along the chordwise direction,and the fluctuating signals of unsteady flow were collected in the tip region. The results show that the axial and tip inlet angles of the compressor performance is improved by 5.40% and 5.93%,respectively. Axial injection can effectively reduce the counter-flow velocity cluster in the channel and delay the circumferential development of leakage flow. The maximum leakage of the tip axial chord is reduced by 20% due to the injection in the direction of the tip inlet angle. At the same time,the development track of the leakage vortex can be effectively changed,and impact of the adjacent pressure surface of the blade can be avoided. Injection can restrain the instability of the tip leakage flow based on the spectrum results.