Fully clocking effect in a two-stage compressor

Turbomachines have inherently unsteady flow fields because of relative motion between rotor and stator airfoils. The important part of the unsteady effects results from the rotor-stator interaction. The main sources of unsteadiness in the rotor-stator interaction are potential flow interaction and wake interaction. Since the distribution of the potential flow and wake in the flow passage depends much on the relative position of blade row, variation in the relative circumferential position (clocking effect) of stator or rotor will change the distribution and consequently result in different multistage performance. The current study presents the experimental result of stator clocking effect in low-speed axial compressor, and performs numerical simulation to investigate the effects of fully (stator & rotor) clocking. In the test, time averaged data were collected. The result of time accurate flow calculation for stator clocking was in good qualitative agreement with experimental data. During the clocking of rotor, the stator was indexed to a position corresponding to maximum efficiency, and 8 clocking positions are compared for each clocking.