Research On Flow Control Technology Of Transonic Tandem Blades

Improving stage load level has always been the goal of compressor aerodynamic design.Tandem blade can break through the limitation of aerodynamic load of conventional layout,and has a good engineering application prospect.In order to explore the three-dimensional flow mechanism of tandem stator and further develop the design theory and method of tandem blade,the flow characteristics of near end wall of tandem blade are studied by numerical simulation method,the interaction mechanism of front and rear row is analyzed,and the parametric modeling research is completed,which provides theoretical support for the development of three-dimensional design technology of tandem blade.This paper mainly includes the following aspects:Firstly,under the constraints of typical geometric parameters of tandem stator,the modeling of reference cascade is completed,and the three-dimensional flow characteristics are analyzed.Under the condition of different attack angles,the evolution law of the secondary flow near the endwall and the growth law of the loss near the endwall are summarized,and the mechanism of the influence of the secondary flow on the aerodynamic load growth is analyzed.Secondly,in order to further explore the three-dimensional flow mechanism of tandem blades and the interaction mechanism between the front and rear row,the comparison was carried out under the conditions of single row front / rear row and tandem.The results show that the typical flow phenomena,such as potential effect,slot jet and wake diffusion,significantly affect the diffusion process of the front and rear vanes,and further affect the aerodynamic load distribution along the flow direction and the end wall loss.Therefore,the interference between the front and rear vanes should be considered in the aerodynamic design of the near end wall of the tandem stator.Finally,in order to determine the selection range of the optimal design parameters of the near end wall of the tandem stator,the parametric modeling research is completed,and the selection rules of the load distribution,consistency distribution,middle arc distribution,swept type and curved type of the front / rear blades and the physical mechanism affecting the near end wall flow are discussed.On this basis,the design principles of the tandem stator blades are summarized.