Abstract: The effect of different forms of blade forward stacking on the performance of axial-flow fan is investigated by CFD method. Firstly, the blade forward stacking condition of an axial-flow fan is designed. Two forms of forward stacking blade, the forward overall-stacking blade and forward mid-stacking blade are proposed. Based on the numerical simulation method, the aerodynamic performance of these two forms of forward stacking blade and baseline blade is calculated and compared. The local Euler head (LEH) and blade loading in the flow field of impeller are extracted to reveal the mechanism of these effects of forward blade stacking on aerodynamic performance. The results show that, the blade forward mid-staking could improve the aerodynamic performance of axial-flow fan at the design flow rate and maintain that over the whole flow rate range. At the design flow rate, the blade forward mid-staking makes the blade loading at the impeller tip of axial-flow fan more concentrated in the front part, which is benefit to suppressing the tip leakage of impeller and improve the efficiency of fan.

Key words: Blade stacking, Axial-flow fan, Local Euler head, Blade loading