A serrated leading-edge blade for a multi-blade fan of an air conditioner is designed. The main objective is to reduce the vortex near the blade

thus reducing the flow loss and aerodynamic noise of the flow field of the multi-blade fan. Whereas it is different from the common reformed blade

no improvement in the width of the whole blade but a front disk along the leading edge by one-third of the impeller width was made. The various serrated structures were simulated based on the geometric-similarity principle using the FLUENT software. The simulated results show that the serrated structures destroyed the accumulated vortex close to the front disk. In contrast to the prototype blade

all vortices in the volute tongue

trailing edge

and internal leaves were obviously decreased with the use of the serrated blade. Meanwhile

the fundamental frequency noise was decreased. The experimental data indicated that the air volume of the leading-edge serrated blade of the centrifugal fan varied a little under different speeds. The noise and input power were decreased by 0.9–1.2 dB (A) and 2.75–3.55 W

respectively. Thus

the serrated leading-edge blade can not only benefit the air-duct performance but also play a role in energy savings and noise reduction.