叶尖小翼对轴流风机气动性能及噪声特性影响的数值研究

To reduce aerodynamic loss and noise caused by the tip leakage flow in an axial flow fan, fused winglets are added on the top of the blades of the axial flow fan. The influence of winglets on the flow field and sound field of the axial flow fan are investigated with numerical method of large eddy simulation and FW-H acoustic analogy. The tip leakage flows are compared under the influences of winglets with different camber angles. Analyzing the flow field and sound field, and comparing the vorticity distributions around the fused blade tip winglets with different camber angles and the surface sound pressure pulsation, the effect of the different camber angle of winglets on the tip leakage flow and the influence of the tip winglets on the fan aerodynamic performance and noise characteristics are discussed. The results show that the winglet can effectively control the development of tip leakage vortex and tip separation vortex, reduce the aerodynamic noise of the axial flow fan, and improve the static pressure efficiency of the axial flow fan. The static pressure efficiency increases by 1.1% and noise decreases by 5.0 dB by utilizing the blade tip winglets with 20° camber angle. The aerodynamic noise caused by tip leakage flow is mainly broadband noise, and the winglet can significantly weaken the broadband noise. Optimizing the camber angle of the winglet, the noise reduction can be achieved without damaging the aerodynamic performance.