The Research Of Separation Flow Control In A Compressor Using Wet Compression

There are two kinds of unsteady conditions called surge and stall in a compressor. Surge andstall will happen when the inlet mass flowrate of a compressor decreases and air separates fromthe blade suction surface severely. The boundary layer blowing technology can make thecompressor which has stayed in surge and stall work at a steady condition and it’s realized byejecting a little high velocity flow into the separation region where the low energy flowaccumulates. In wet compression, if the tiny droplets with high velocity could be used to blowthe low energy flow in separation region, the separation flow can be controlled and the steadywork region of a compressor will enlarge. Meanwhile, the droplets can decrease the airtemperature and cut down the compression work a lot.This paper would investigate how to use the droplets to blow the low energy flow inseparation region. The influences of different spraying positions, ejection angles, dropletvelocities, droplet flowrates and droplet diameters on the performance and flow field of ahighly-load compressor cascade would be researched carefully. The reason to choose such acompressor cascade is that there is an obvious separation region on its suction surface and thetotal pressure of the air flowing through this region would loss a great. At this cascade, theprinciples choosing suitable spraying parameters have been confirmed.On the basis of the research above, another research has been implemented on the7thstageof the core compressor in GE Company’s high efficiency, low energy consumption andenvironment safety (E3) aero engine. The target of this research is to study the influences offogging on the static blade suction surface on the surge line. Under different rotation speeds, theeffects of spraying on the flow field of the compressor stage have also been investigated.All the cases involved in this paper are calculated by the commercial CFD softwareANSYS/CFX, and the grid herein are produced by the IGG/AutoGrid tool which is developed byNUMECA company.