Experimental and Numerical Investigation of the Unsteady Endwall Flow in a Highly Loaded Axial Compressor Stator

Abstract

The unsteady endwall pressure distribution is investigated by means of highly resolved pressure measurements and numerical simulations in an axial compressor stator exhibiting the phenomenon of rotating instability. The endwall flow has been observed to play an important role in the inception of rotating instability. The statistical properties of the measured pressure fluctuations at the hub endwall of the axial compressor stator are compared for a series of blade loadings. The results allow conclusions about the location of regions being closely connected to the unsteady dynamics related to the rotating instability phenomenon. Furthermore the operating points with detected rotating instability are compared with unsteady numerical results.