Investigation Of Transonic Compressor Performance Affected By Boundary Layer Suction In Stator

The high efficiency and high load design indexes of modern aero engines have put forward higher and higher requirements on the efficiency and load level of the compressor,the increase of blade load will make the transverse pressure gradient inside the blade passage and the two flow strengthen,boundary layer of suction surface easy to produce large scale flow separation,the loss of cascade increases rapidly,the stall margin and efficiency of the compressor decreases sharply.High efficiency and high load aerodynamic performance requires higher requirements for the design of compressor blades as the core components,the active flow control technique,boundary layer suction technique,can effectively improve the blade load and the distribution of pressure gradient,effectively control the development of the boundary layer,thus,the single-stage pressure ratio and efficiency of the compressor are improved,and the loss is reduced.In this paper,by using the CFD numerical simulation of numerical experimental calibration method,under different working conditions of the stator flow field was simulated and analyzed,and found the location of flow separation.The stator passage of the transonic compressor is subjected to boundary layer suction,the suction scheme mainly involves openings a slot suction on the stator suction surface;flow and spanwise suction slots on the static cascade endwall and suction blade and endwall combined suction.Through the analysis of limit streamline,blade surface pressure,each section of the total pressure loss coefficient and Mach number distribution parameters,found that the main reasons for the flow loss and the flow control scheme for flow field with boundary layer suction.Firstly,the contrast of the prototype on the suction side boundary layer suction hole/slot scheme in different suction volume,reduces the thickness of the suction surface to flow boundary layer,enhance the boundary layer kinetic energy,corner separation scale reduction.With proper increase of suction flow,the endwall effect is reduced,and the range of corner separation and reflux is reduced more effectively.Then,the endwall boundary layer suction to the suction slot scheme scheme significantly in addition to absorbing energy fluid directly blocking the radial migration of endwall boundary layer of low-energy fluid to the suction surface side,reduce the accumulation of low energy fluid in the suction surface and endwall corner region,closed separation vortex sucked,convection to reduce road congestion,delay the occurrence of the compressor stall.Thirdly,amplitude of lateral migration of circumferential groove endwall boundary layer suction scheme effectively reduces the flow boundary layer,weaken the ability of low-energy fluid to the suction surface of middle blade migration,delayed corner separation,lateral two flow restrain.Finally,the combined suction scheme of the suction surface and the endwall combines the advantages of the two methods of single slot suction,the interaction between the endwall boundary layer and the suction surface boundary layer is better controlled,the corner separation is significantly reduced,the aerodynamic performance of stator is improved obviously,the application value of combined suction is shown.