Influence Of Tip Winglet Combined With Groove On The Tip Clearance Flow Of Compressor Stator

In the compressor with cantilever type stator structure,there is a certain gap between the tip of the stator and the hub,which causes part of the fluid to move from the pressure surface to the suction surface of blade and cause the tip leakage under the action of the pressure difference on both sides of the blade.The leakage flow is mixed with the main flow to form a tip leakage vortex,and the tip of the blade leakage along the flow direction of the low-energy fluid in the vortex end region.This not only causes the tip leakage loss,but also blocks the cascade flow passage,reduces the effective flow area,and in severe cases causes the compressor to stall and reduce the aerodynamic performance of the compressor.The study of the gap leakage flow and the adoption of appropriate control measures are of great significance for improving the secondary flow inside the compressor,reducing the flow loss and improving the aerodynamic performance of the compressor.In order to reveal the control mechanism of the suction surface winglet combined with the tip groove on the performance of the compressor cascade and its clearance flow,a low-speed compressor plane cascade was studied by numerical simulation.The results show that the different width suction surface winglet scheme and the suction surface winglet combined with the tip groove scheme can control the tip leakage flow and reduce the cascade loss.In the scheme of only adding the winglet,the reduction of the total pressure loss of the suction surface winglet scheme SW2.0 with the width of 2.0 times of the blade is the largest;in the scheme with the tip groove,The winglet combined with groove scheme GSW1.0 with the width of 1.0 time of the blade has the best improvement effect.In addition,the groove at the top of the blade also reduces the weight of the blade due to the addition of the tip winglet.In order to simulate the:flow state of the real flow field inside of the compressor,the influence of the suction surface winglet combined with the tip groove on the tip leakage flow is studied in this paper.The numerical results show that in the relative motion of the endwall,the suction surface winglet scheme and the suction surface winglet combined with the tip groove scheme have a certain degree of control on the cascade leakage flow and reduce the cascade loss.In order to investigate the influence of the thickness of the inlet boundary layer on the effect of the suction surface winglet combined with the tip groove scheme on the control of the tip leakage flow,the scheme of the suction surface winglet combined with the tip groove cascade of the different suction layer thickness is carried out.The effects of the clearance flow field and the aerodynamic performance of the cascade are studied.The numerical results show that the suction surface winglet and the combined tip groove can effectively improve the compressor cascade loss and reduce the tip clearance leakage and the flow intensity under different thickness of the boundary layer.With the thickness of the boundary layer increases,the damage reduction effect of the single suction surface winglet scheme is reduced,and the damage redution effect of the suction surface winglet combined with the tip groove scheme is increased.