Experimental investigations of flow instabilities in a single-stage axial compressor

At the Laboratory for Turbomachinery and Fluid Power (TFA) of the Darmstadt Universitiy of Technology experimental investigations of flow instabilities have been carried out in a single-stage low-speed axial compressor. Exceeding the stable operating range a part span rotating stall arises inside the compressor stage propagating with approximately half the rotor speed. The transition process into rotating stall and the extent of the fully developed stall cell were studied with dynamic pressure transducers flush mounted at the casing wall and traversed at several radial locations upstream and downstream of the rotor. The influence of varied operating parameters as rotor speed, stagger-angle of the rotor and IGV was proved on the stall inception point in the steady state operating map, on the initiation event and the extent of the stall cell.