多级压气机喘振边界点的通道流动特征

Passage Flow Characteristics of Multistage Compressor at Surge Boundary

进行台架试验,获取了试验发动机喘振边界点的压气机通道压力信号。对压力信号进行了频谱分析,以确定喘振边界点的通道流动特征。分析结果表明,与高转速时流动状态较好的情形相比,发动机工作点处于喘振边界时,压气机第1级静子通道压力信号频率成分中,第1、2级转子叶片通过频率信号BPF1、BPF2和以550 Hz为中心的谐波成分幅值显著增强,在550Hz附近出现多根强幅值的谱线;从较高转速减速时,BPF1、BPF2的幅值先是迅速增大,随后随工作转速减小而逐渐减小,与此不同的是,550 Hz附近频率成分则是随转速减小而逐渐增强的。对试验发动机而言,所获得的喘振边界点通道流动特征可望用于压气机工作稳定性的实时监控和预警。

Engine rig tests are performed and compressor passage flow pressure signal at surge boundary is obtained. Spectral analysis is adopted to investigate passage flow characteristics at surge boundary. Among all the frequency contents of the pressure signal of the first compressor stator passage, compared with higher rotor speeds at which the flow matches well, the magnitudes of BPF1 and BPF2 the blades are passing frequency contents for the first two compressor rotors respectively and the magnitudes of harmonic frequency contents near 550 Hz increases obviously at surge boundary, and a few spectral lines with very high magnitudes appear near 550 Hz. In the process of reducing rotor speeds from high speed, the magnitudes of BPF1 and BPF2 rapidly increase at first, and then gradually decrease; while the intensity of the frequency contents near 550 Hz gradually increases with the decrease of rotor speed. As for the test engine, the passage flow characteristics at surge boundary might be helpful to the monitoring and early -warning of compressor operation stability.