定常微量喷气提高轴流压气机稳定工作裕度机理探讨

顶部喷气是提高压气机稳定工作裕度的有效方式之一。文中设计了一种新型的喷嘴结构,利用高速单级轴流压气机试验台,研究了定常微量喷气对压气机性能和稳定工作裕度的影响。试验结果表明:在53%设计转速下,占压气机设计流量0.064%的喷气量可以使得压气机的失速裕度提高7.69%。同时,对带定常微量喷气的压气机转子内部流动进行了时间精确的非定常数值模拟,对比分析了喷气前后转子顶部区域不同的流动结构。将顶部间隙泄漏涡轨迹向压气机转子尾缘推移,抑制来流/顶部间隙泄漏流交接面向转子叶片前缘移动是定常微量喷气提高压气机失速裕度的主要机理。

Exploring Mechanism of Stall Margin Enhancement of Subsonic Axial-Flow Compressor through Steady Micro Tip Injection

Aim.Suder et al dealt with the same problem with numerical simulation only[5];in our opinion,the mechanism they offer,lacking experimental support,is representative of several brave but unsuccessful first attempts at exploring this very difficult subject.We believe that the mechanism we offer,with some experimental support,is a step forward.In the full paper,we explain in detail the results of our exploration;in this abstract,we just add some pertinent remarks to listing the four topics of explanation:(1) test setup and the design of injector,(2) the analysis of the test results,(3) the method of numerical simulation,and(4) the results of numerical simulation and their analysis;under topic 1,we explain a new type of injector with the help of Fig.1in the full paper;in topic 2,we point out that,for the tested rotor,our experimental results demonstrate that the stalling mass flow can be reduced by 7.69% using an injected mass flow equivalent to 0.064% of the design mass flow at 53% design speed;in topic 3,we point out that time-dependent CFD simulations were conducted with a view to identifying the physical mechanism that accounts for the beneficial effects of the steady micro tip injection on the performance and stability of the subsonic axial-flow compressor;also under topic 3,Fig.3 in the full paper shows the performance of the rotor of the tested subsonic axial-flow compressor; in topic 4,we give detailed analyses of the flow visualization at the tip that expose the different tip flow topologies for the cases without tip injection and with tip injection as shown in Fig.4 in the full paper.It is found that the physical mechanisms responsible for extending the compressor stall margin is repositioning the tip clearance vortex trajectory further towards the trailing edge of the blade passage and delaying the movement of incoming/tip clearance flow interface to the leading edge plane.