级间引气对多级轴流压气机性能和流场影响的低速实验研究

Low Speed Experimental Investigation of Inter-Stage Bleeding Effect on Performance and Flow Field of Multistage Axial Compressor

关键词:  多级轴流压气机  级间引气  径向掺混  流场  实验研究

Key words:  Multistage axial compressor  Inter-stage bleeding  Spanwise mixing  Flow field  Experimental investigation

摘要:

为了研究级间引气对多级轴流压气机性能和流场的影响机理，基于北京航空航天大学的四级低速大尺寸压气机实验台，在二级静子出口进行周向槽引气，采用分别保持引气位置上游流量不变和引气位置下游流量不变两种比较方式，针对不同引气流量大小对压气机性能和内部流场的影响进行了实验研究。结果表明，级间引气会影响压气机压升特性和失速裕度，影响程度与引气量大小有关。级间引气对引气位置上游转子流场的影响表现在上游压气机工况的变化上，上游转子流场的展向分配并不受到引气的影响。引气位置下游受到引气和上游压气机工况变化的共同影响，且引气量越大，影响程度越大。此外，级间引气可以改善下游叶片叶尖区域的流动环境，增强叶尖处流通能力，提高下游压气机失速裕度。

Abstract:

For purpose of investigating the mechanism of inter-stage bleeding， based on the four-stage low-speed large-scale research compressor test rig in Beihang university， experimental investigation of bleeding effect on performance and flow field of multistage axial compressor is carried out. The bleeding structure is circumferential slot located downstream of second stage stator. Varies of bleeding mass flow rate are presented with two comparison methods， keeping mass flow rate the same upstream of bleeding location and downstream of bleeding location， respectively. The results demonstrate that inter-stage bleeding affects compressor pressure rise characteristic and stall margin， and extent of influence is concerned with bleeding rate. Compressor operating condition upstream of bleeding location changes due to the influence of bleeding， while the spanwise distribution of flow field upstream of bleeding location has no change. Flow field downstream of bleeding location is affected by not only inter-stage bleeding， but also the change of operation condition upstream of bleeding location， and extent of influence increases with bleeding rate increasing. In addition， inter-stage bleeding could improve downstream flow capacity at tip region， therefore increase downstream compressor stall margin.