Active Control Of Vortex Generator Jet To The Endwall Flow In Compressor Cascade

As compressor is one of the core components of aircraft engine, theimprovement of its performance is an important method to improve the totalperformance of the aircraft engine. The investigation and design of high pressureratio and high efficiency compressor has great significance for the development ofthe aircraft engine.One important way to improve the loading of compressor cascade is to uselarge turning blade, but with the increasing of the blade turning angle, the transversepressure gradient of the cascade will increase and the secondary flow will intensify,which will make flow separation easier and increase the losses, leading to the reduceof the compressor performance. So, how to control the flow separation in cascadeproperly and reduce the flow losses is an important direction in compressor design.Through numerical simulation of the flow in compressor cascade usingcommercial software CFX, the control of vortex generator jet on high turningcompressor cascade is studied in this thesis. At design incidence, by changing theparameters of the jet tube, three different comparing programs was got, that isdifferent axial position, different circumferential position and different side angle ofjet tube, and studied the influence of axial position, circumferential position and sideangle of jet tube on the flow in compressor cascade. The control mechanism ofvortex generator jet on the flow of compressor cascade end wall was also analyzedthrough the vorticity distribution and secondary flow streamline of different sectionsin the cascade. In addition, a research on the effect of vortex generator jet oncompressor cascade at undesign incidence was also made in this paper, analyzing therelationship between the control effect of vortex generator jet on the flow incompressor cascade and the attack angle.The results show that at design incidence vortex generator jet of all axialposition in the simulation makes good effect on the flow separation in thecompressor cascade, and can also reduce the total pressure loss. Among all the planof different axial position, the jet tube located-10%axial chord length from theleading edge makes best effect. There is great relationship between the effect thatthe vortex generator jet made on the compressor cascade and the circumferentialposition, only the plan when the jet tube located10%circumferential pitch from thesuction side can make positive effect on the flow in compressor. The side angle ofthe jet tube can change the intensity of the streamwise vortex through changing theangle between the jet flow and the main flow. When the side angle varies from-20°to0°, the vortex generator can all make apparently positive effect on the flow in the compressor cascade. With the increasing of the side angle, the control effect of thevortex generator jet weakens. Besides, the effect of vortex generator jet on the flowof compressor cascade will be more and more obvious with the increase of the attackangle, and the total pressure loss coefficient can be reduced by32.91%at the attackangle of5°.