Effects of Blade With Perforation on Aerodynamic Performance of Dual-Rotor Small Axial Flow Fans

The static characteristics of dual-rotor small axial flow fans are better than that of single rotor small axial flow fans. While, compared with single rotor small axial flow fans, the noise of dual-rotor small axial flow fans highly increases. Regarding to this reason, the perforation blade are designed for dual-rotor small axial flow fans in this paper. Pre-stage blades, post-stage blades, and both pre-stage and post-stage blades were perforated respectively. The k–ε turbulence model and the FW-H noise model were used to simulate. Then, the static characteristics and aerodynamic performance of the prototype fan and the fans with perforation blade were contrasted and analyzed. The results show that: In general, the pressure rising and efficiency of the fans with perforation blade declines slightly. Compared to another two perforation blade, and the pressure rising and efficiency of the fans of pre-stage perforating fan shows the smallest reduction, but increases slightly at the optimum operating condition; With the difference of perforation way, the variation of the noise level are different, while, in the outlet zones, the noise are all reduced;. The centralized region of vorticity in the trailing edge of the blades are reduced, and the noise of the fans are all reduced. All the results show that, using perforation blade can improve the aerodynamic performance of dual-rotor small axial flow fans.