Three-dimensional characteristics of turbulent plow in tip region inside an axial-flow compressor rotor passage

Three-dimensional characteristics of turbulent flow in the tip region was studied using a 3-D Laser Doppler Velocimetry inside an axial-flow low-speed large-scale single-stage compressor rotor passage. The flow was surveyed across the entire passage at fifteen axial locations (leading edge to trailing edge) and twelve radial locations (0.985, 0.980, 0.975, 0.950, 0.925, 0.900, 0.875, 0.850, 0.813, 0.775, 0.738, 0.700 span). This paper presents the variations of axial, tangential and radial turbulence intensity and stresses in design condition. The measurement results indicated that, the strong interaction of the tip leakage vortex, the annulus wall boundary layer and the main flow produces high turbulence, which develops with the leakage vortex, and the radial turbulence intensity was found to be the largest while the axial-radial Reynolds stress is the largest. The presence of the highest level of turbulence intensities at 1/3 chord indicates the strongest flow mixing nearby. Bursting of the leakage vortex makes the flow more turbulent in the larger region downstream. The corner vortex contributes to the high turbulence level at the corner between the casing and the suction surface.