交替静叶布局对轴流压气机气动稳定性的影响

Effects of alternating-stator vane layout on aerodynamic stability of axial compressor

关键词:  轴流压气机  交替静叶  角区分离  稳定裕度  进口几何角

Key words:  Axial compressor  Alternating-stator vane  Corner separation  Stability margin  Inlet metal angle

摘要:

为揭示交替静叶布局控制角区分离的流动机理，提升压气机性能，实现压气机的扩稳，采用了数值模拟方法对某高负荷跨声速压气机展开交替静叶设计研究。通过改变静叶叶尖进口几何角，调整叶片的布局方式，得到一种改叶型弯角交替静叶，在此基础上结合叶片弦长进一步优化，得到另一种改弦长交替静叶。数值研究表明：改叶型弯角交替静叶布局压气机的稳定裕度相对原型提升了34.7%，改弦长交替静叶使改叶型弯角交替静叶的压气机稳定性进一步提高，但会造成压比和效率的小幅下降，即以损失部分性能的代价换取了压气机稳定性的提升，改弦长交替静叶压气机在前者基础上将稳定裕度进一步提升了9.7%。新型的静叶布局使得相邻流道的流场结构产生差异，在周向上形成上、下角区分离交替分布的格局，促进了相邻流道出口流体的汇聚。叶型弯角的改变使角区低能流体区引入了更多高能流体，抑制了低能流体在角区堆积，提升了静叶的扩压能力。而弦长改变的同时增加了叶片前掠，阻隔了部分气流，实现了气流的重新分配，一定程度上平衡了两侧气流流量的不均匀性，从而改善了该压气机的气动稳定性。

Abstract:

To elucidate the flow mechanism of controlled corner separation in an alternating-stator vane layout and improve the performance of the compressor， enabling compressor stability， a numerical simulation was employed to investigate the design of an alternating-stator vane configuration for a high-load transonic compressor. By varying the geometric angle at the stator vane tip inlet and adjusting the vane layout， a modified vane angle alternating-stator （AS） was developed. Additionally， further optimization was performed by incorporating changes in chord length， resulting in a modified chord length alternating-stator （CAS）. The numerical investigation revealed that the stability margin of the compressor with the AS layout improved by 34.7% compared to the original compressor. The CAS further enhanced the stability of the AS compressor， albeit at a slight cost of reduced pressure ratio and efficiency. This trade-off allowed for the improvement in compressor stability while sacrificing some performance. The CAS increased the stability margin by an additional 9.7% compared to the previous design. The novel stator vane layout induced variations in the flow field structure between adjacent passages， creating a pattern of alternating separation and convergence zones in the circumferential direction. This pattern facilitated the convergence of fluid at the exit of adjacent passages. The alteration of vane angles introduced a greater quantity of high-energy fluid into the low-energy fluid region， suppressing the accumulation of low-energy fluid in the separation zones and enhancing the diffusion capability of the stator vane. Simultaneously， the change in chord length increased vane sweep， impeding a portion of the airflow and redistributing it. Consequently， this adjustment balanced the unevenness in airflow on both sides to a certain extent， thereby improving the aerodynamic stability of the compressor.