Study On The Effect Of Suction Structure And Parameters On The Boundary Layer Oscillation Suction

With the unremitting pursuit of the thrust-weight ratio of the aircraft,the compressor is developing in the direction of reducing the number of stages,increasing the stage pressure ratio and the total pressure ratio.Compressors designed within the range of conventional reaction degree are constrained by material strength and shock wave loss,so the speed of the compressor cannot be too high,making it difficult to further increase the load on the compressor.In this context,low reaction high load axial flow compressor based on flow control comes into being.Therefore,the research of stable and reliable flow control technology will lay a solid foundation for the practical application of low reaction high load axial flow compressor.Researchers in the field of turbomachinery have carried out many theoretical,numerical simulations and experimental studies on the suction of the boundary layer.However,most of them extract partial meshes on the wall and then impose boundary conditions merely,which are more or less different from the actual situation.In this paper,a suction cavity is added inside the blade,and the gas in the cascade flow channel is sucked through the full-span height and spanwise groove,which is closer to the actual suction condition.In this paper,the effects of different suction structures and parameters on the oscillation suction of the boundary layer are studied.The results show that under the condition that the relative mass flow rate of suction is 1%,there is a significant effective threshold for the oscillation frequency and the relative oscillation amplitude of suction for different suction structures.When the oscillation suction is applied in this threshold,it will significantly control flow separation near the end wall and the middle of the blade.Under the condition that the other suction conditions are consistent,the larger the control size of the suction cavity,the better the control effect on the flow field.There is also a significantly effective threshold for applying the oscillation suction of the boundary layer.Applying the oscillation suction control of the boundary layer within this threshold can significantly control the flow separation near the end wall and the middle of the blade.Beyond this range,the flow field of the cascade is rapidly deteriorated,and the flow control is almost ineffective.Applying boundary layer oscillation suction control to the cascade can transfer some of its physical properties to the cascade flow field,such as the oscillation frequency and the relative amplitude of the suction oscillation.