Turbulent flow field in the tip region of an axial-fiow fan rotor was measured using a3-D LDV(Laser Doppler Velocimetry). The flow was surveyed across the entire passage atseven axial locations (leading edge, 1/6 chor...Turbulent flow field in the tip region of an axial-fiow fan rotor was measured using a3-D LDV(Laser Doppler Velocimetry). The flow was surveyed across the entire passage atseven axial locations (leading edge, 1/6 chord, 1/3 chord, 1/2 chord, 2/3 chord, 5/6 chordand trailing edge) and eight radial locations(0.983, 0.967,0.942, 0.917, 0.883,0.833, 0.750 and0.667 span). The data derived include all three components of mean velocity and turbulenceintensity. The measurement results indicated that the tip leakage vortex produces very nearthe leading edge, and it becomes strongest at the half chord, then decays rapidly. At theexit of the rotor passage, the leakage vortex exists in mid-passage. In the corner betweenthe casing wall and the pressure surface, the scraping vortex becomes stronger with the flowdownstream, leading to more substantial turbulence and blockage. The tip leakage vortexplays a leading role in the tip flow field of the rotor passage, producing most flow turbulenceand blockage.展开更多
文摘Turbulent flow field in the tip region of an axial-fiow fan rotor was measured using a3-D LDV(Laser Doppler Velocimetry). The flow was surveyed across the entire passage atseven axial locations (leading edge, 1/6 chord, 1/3 chord, 1/2 chord, 2/3 chord, 5/6 chordand trailing edge) and eight radial locations(0.983, 0.967,0.942, 0.917, 0.883,0.833, 0.750 and0.667 span). The data derived include all three components of mean velocity and turbulenceintensity. The measurement results indicated that the tip leakage vortex produces very nearthe leading edge, and it becomes strongest at the half chord, then decays rapidly. At theexit of the rotor passage, the leakage vortex exists in mid-passage. In the corner betweenthe casing wall and the pressure surface, the scraping vortex becomes stronger with the flowdownstream, leading to more substantial turbulence and blockage. The tip leakage vortexplays a leading role in the tip flow field of the rotor passage, producing most flow turbulenceand blockage.
