Experimental Investigation on Circumferential Propagation of Tip Leakage Flow in Axial Compressor

The circumferential propagation of the disturbance which is dominated by the unsteadiness of tip leakage flow has been studied base on the unsteady measurement along the blade chord and circumferential direction in this paper.Then the evolutions from the unsteadiness of tip leakage flow to stall inception with throttling of the compressor are analyzed further.The experimental results indicate that the circumferential propagation speed of the unsteady tip leakage flow will increase during the throttling process,this phenomenon will occurs only after the appearance of the unsteadiness of tip leakage flow.It demonstrates that the unsteadiness of tip leakage flow is the basis of the analysis and prediction on stall inception,and also provides the guidance of understanding of the uniform flow mechanism between the unsteady tip leakage flow and stall inception process.