摘要
Three different inlet configurations,including a original straight pipe and two bend pipes with different axial length,for a high speed low mass flow centrifugal compressor were modeled with whole blade passages and simulated unsteadily by 3D viscous Navier-Stokes equations.The performance disparities of compressor stage were tested and verified by experiments in which dynamic pressure data acquisition of internal flow field was performed.As the result shows,the choke point decreases to lower mass flow rate due to the distortion caused by bend-pipe inlet and is aggravated as the rotation speed increases.The distortion effect spreads circumferentially in impeller and makes the flow structure varied.The longer axial distance bent inlet leads to larger radial distortion and heavy blockage at mid-span under large mass flow mainly causes compressor choke margin nar-rowed.Bend pipe distortion brings an impact up to diffuser on unsteady pressure pulsation caused by blades sweep and the impact appears more powerful when it is closer to volute tongue.
Three different inlet configurations, including a original straight pipe and two bend pipes with different axial length, for a high speed low mass flow centrifugal compressor were modeled with whole blade passages and simulated unsteadily by 3D viscous Navier-Stokes equations. The performance disparities of compressor stage were tested and verified by experiments in which dynamic pressure data acquisition of internal flow field was performed. As the result shows, the choke point decreases to lower mass flow rate due to the distortion caused by bend-pipe inlet and is aggravated as the rotation speed increases. The distortion effect spreads circumferentially in impeller and makes the flow structure varied. The longer axial distance bent inlet leads to larger radial distortion and heavy blockage at mid-span under large mass flow mainly causes compressor choke margin nar- rowed. Bend pipe distortion brings an impact up to diffuser on unsteady pressure pulsation caused by blades sweep and the impact appears more powerful when it is closer to volute tongue.
基金
supported by Chinese Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20101101110009)
the National Natural Science Foundation of China (Grant No. 51176013)
关键词
离心的压缩机
入口失真
数字模拟
动态数据获得
centrifugal compressor, inlet distortion, numerical simulation, dynamic data acquisition
