Experimental investigation of stator clocking in a centrifugal compressor

The Clocking phenomenon has been detected in the axial compressor by experimental and numerical investigation, but have very few report on the centrifugal compressors. The current study presents the experimental result of stator Clocking effect in low-speed centrifugal compressor. An experimental research program has been performed to study the performance variations associated with airfoil Clocking. And the flow fields have been measured with hot-wire probes at the impeller outlet and the diffuse inlet. The results demonstrate that Clocking effects on the efficiency are obvious. The airfoils Clocking effect on the stage efficiency is more than 2% and the maximum is about 3.6%. At different Clocking positions, the ensemble-averaged velocity components change 3.3% in the tangential direction and 16.5% in the radial direction at the impeller outlet. At the diffuse inlet, the changes exceed 2% in the tangential direction and 4% in the radial direction. And the absolute flow angle alters about 1.5 degree at the diffuse inlet.