旋流畸变影响低速轴流压气机数值模拟研究

Numerical Simulation of Low Speed Axial Compressor with Swirl Distortion

为研究进气旋流畸变对轴流压气机性能和稳定性影响的机理,设计了一种叶片式旋流畸变发生器,分别采用定常和非定常计算方法对旋流畸变发生器和两级低速轴流压气机进行了联合数值模拟研究。定常计算结果表明:旋流畸变发生器的叶片弯角越大、对涡强度越高;对涡旋流导致压气机总压比和效率降低,稳定边界流量明显增加;对涡强度越大,对压气机性能和稳定性影响越严重;对涡的反向涡对压气机影响较大,同向涡影响较小;反向涡造成部分叶片的叶根区域吸力面附面层提前分离,是导致压气机失稳的主因;非定常解的总压比和效率均略高于定常解,两种计算方法得到的稳定边界差异明显,非定常解的稳定边界流量比定常解小19.2%,非定常计算结果更接近试验值。

In order to investigate the effect of swirl distortion inlet flow on performance and stability of axial compressor,blade swirl distortion generator was designed and numerically simulated with a two-stage low speed axial compressor using steady and unsteady calculation methods, respectively. The steady simulation results show that the intensity of twin-swirl generated by blade swirl distortion generator can be increased by using blade with larger turning angle. Total pressure ratio and efficiency will decrease under twin-swirl,and mass flow at stability boundary increases greatly. The effects of twin-swirl on performance and stability of compressor enhance as swirl intensity increases. Twin-swirl contains a co-rotating swirl and a counter-rotating swirl. The counter-rotating swirl has great impact on compressor,and the influence of co-rotating swirl is small. The counter-rotating swirl results in boundary layer separation of the suction surface in part of blades around the hub,which is the main reason to make compressor unstable. Total pressure ratio and efficiency using unsteady calculation method are a little larger,but mass flow at stability boundary will change significantly,and unsteady result is about19.2% lower than steady one. The unsteady simulation results are more close to experiment data.