转子叶尖间隙对高负荷压气机性能影响的数值计算和试验验证

Numerical Calculation and Experimental Verification of Rotor-tip-clearance Effects on High-Load Compressor Performance

为了研究高负荷压气机转子叶尖间隙对压气机性能的影响,采用数值模拟软件NUMECA对某4级压气机和其中的1个典型级进行了不同间隙的计算。计算结果表明:当间隙超过叶高的0.52%后,叶尖流场出现堵塞,喘点压比衰减速度开始加剧,直至5.24%性能衰减速度逐渐减弱;在多级环境中,4级压气机间隙增大叶高的0.5%,喘点压比降低了约0.6%~4.3%,间隙增大的叶排作功能力降低是压气机喘点总压比降低的主要原因,其中前2级间隙增大对总性能影响较大。同时,通过4级压气机试验验证了间隙对性能的影响,验证结果表明:间隙增大叶高的0.78%后,4级压气机喘点压比和峰值效率分别降低了1.4%和0.4%,在65%~88%叶高时的压比和效率的性能衰减较为明显。

In order to analyze the effect of rotor-tip-clearance on the performance of high-load compressors,simulations of a four-stage compressors and one typical stage with different clearance were calculated by NUMECA.The calculation results show that when clear-ance exceeds 0.52%span,tip flow blockage emerges,and the attenuation rate of the surge-point pressure ratio begins to intensify until the tip clearance reaches 5.24%span,the performance attenuation rate gradually weakens;In the multi-stage environment,with a 0.5%span tip clearance increase,the total pressure ratio reduces about 0.6%to 4.3%.The working capacity decrease of the blade row with increased clearance is the main reason for the decrease of the surge-point total pressure ratio,with the clearance increases of the first two stages hav-ing more significant impact on the overall performance.Meanwhile,the influence of the clearance on performance was verified by the four-stage compressor experiments.The verification results show that if the clearance increases 0.78%span,the surge-point total pressure ratio and peak efficiency of the four-stage compressor are reduced by 1.4%,0.4%respectively,with the performance degradation of the pressure ratio and efficiency more significant at 65%to 88%spanwise position of the blade.