Experimental Study on the Noise Characteristics of Local Contra-Rotating Axial Fan Used in Mines

By means of testing study of the noise characteristics of four kinds of local contra-rotating axial fan for coal-mine,the noise spectra curves and the variation curve of A-weighted sound level corresponding to various operation points are acquired.The discrete noise spectra characteristics are also analyzed in detail.It is found that the noise corresponding to the blade passing frequency(BPF) of the first impeller and the blade interaction frequency(BIF) between the two stage impellers is the primary discrete noise sources of the local contra-rotating axial fan.This work provides a useful reference for decreasing contra-rotating axial fan's noise.