Numerical investigation on tonal noise of fan with local porous wavy leading edges

For the suppression of rotor-stator interaction tonal noise, a combined configuration of porous material and wavy leading edge was proposed. A hybrid acoustic/flow field method was employed for tonal noise prediction. The aerodynamic performance and tonal noise of the baseline fan, the wavy leading edge fan and the local porous wavy leading edge fan were compared. The results show that the local porous wavy leading edge has a greater impact on the fan aerodynamic performance than that of the wavy leading edge. The local porous wavy leading edge resulted in a decrease of 0.007 0 in the total pressure ratio and a reduction of 3.67% in efficiency. Compared to the wavy leading edge, the local porous wavy leading edge demonstrates a significant improvement in noise reduction performance. Specifically, it reduces the tonal noise by 8.6 dB at the first blade passing frequency. The local porous wavy leading edge effectively suppresses the strong pressure fluctuations at the wavy trough, while maintaining the alteration in the phase of pressure fluctuations, thus further reducing the tonal noise.