Abstract:  Aiming at the problem of high noise generated by the rotation of centrifugal fan blades during operation, the windward surface structure of the blades was taken as the object of study, and the acoustic performance of the blades was simulated. The influence of blade perforation on the acoustic performance of centrifugal fan was analyzed. Firstly, the windward surface of the blade was perforated, and the effect of different perforation shapes, different perforation diameters, and different porosity on the fan noise was investigated using FLUENT simulation software. Then, the effect on the acoustic performance of the fan was discussed after the blade was filled with porous media material. Finally, orthogonal experiments of original blade, blade perforation, blade perforation and filling material were carried out, and the reliability of simulation results of different blade perforation structures was verified by experiments. The simulation results show that when the perforation shape is round, the perforation diameter is 1.5 mm, and the porosity is 5%, the fan noise is reduced by 5.6%. After the blade is filled with porous media material inside, it can further reduce the fan noise. Comparing with the original blade, the noise reduction effect is improved by 9.1%, and the negative pressure performance of the fan is improved by 11%. Experimental results show that blade perforation and material filling can increase the noise reduction effect by 5.3% and air volume by 7.5%. The research results show that the perforation of the blade surface structure and the inside filling of porous material can effectively reduce fan noise, and the conclusions obtained provide reference for the noise reduction treatment technology of centrifugal fans.
Key words:  fan; centrifugal fan; fan operation noise; perforated plate; acoustic performance; porous media materials