The Impact Of Unsteady Excitation On The Compressor Out Of Instability

In order to study the effect of unsteady excitation on the exit instability of compressor,firstly,the entry and exit instability process of a two-stage low-speed axial compressor is experimentally studied.The frequency analysis method,time-frequency analysis method and wavelet analysis are used to analyze the characterize of the dynamic development and elimination process of the instability signal.After that,the process of formation and disappearance of instability phenomena of the annular cascade is simulated by CFD and the characteristics of instability signals are analyzed by the same data processing method.At the same time,the flow field analysis of the above two processes is carried out.On the basis of studying the dynamic process of exit the rotating stall,the artificial disturbance is generated by the wiggling stator of the downstream,and the difference between the artificial disturbances induced by different wiggling stator projects is described and analyzed in detail.From the analysis,a perturbation method is selected as the man-made disturbances exerted on the compressor exiting the instability process.And the axial velocity perturbation wave formed by this disturbance scheme is analyzed.In the end,the influence of the unsteady excitation on the dynamic process of the compressor from the unsteady state to the steady state is discussed.The numerical simulation results show that the flow coefficient can be reduced by 4.382%,when the unsteady excitation is added to the exit instability process,and the total pressure rise coefficient is increased by 0.926%.