关键词: 离心风机, 气动噪声, 数值模拟, FW-H方程

Abstract: The prediction of aerodynamic noise of centrifugal fans is a key problem that is difficult to deal with in the industrial field. In order to reasonably predict the aerodynamic noise of air purifier, the noise analysis of a certain type of air purifier is carried out by using the research method of numerical simulation and experimental test. Firstly, the steady-state flow field of the simplified purifier model is calculated, secondly, the sound field of different centrifugal impellers is calculated and judged by the large eddy simulation and the FW-H equation, and finally the prediction accuracy is verified by the measured results of the semi-anechoic indoor noise. The research shows that the broadband noise sources inside the fan is mainly located at the volute tongue and the leading edge of the blade at the air flow outlet of the volute; the more vortex area in the blade channel, the greater the broadband noise; through the transient sound field spectrum analysis and octave analysis, the sound quality of different impellers can be judged. Finally, by comparing the sound field simulation results of the two impellers, it is judged that the sound quality of the No. 2 impeller is better than that of the No. 1 impeller, and according to the actual test, the sound quality trend reflected by the spectrum is consistent with the simulation prediction value, which proves that the accuracy of the simulation prediction is good, and provides effective method guidance for the design of the subsequent centrifugal fans.

Key words: Centrifugal fan, Aerodynamic noise, Numerical simulation, FW-H equation