Abstract: In order to control the air flow in centrifugal fan’s impellor, three dimensional blade technology of bowed - swept blade is applied to a certain centrifugal fan. According to the difference of stacking line in the circumferential and meridian surface, eight blades are taken into numerical simulation, including positive-bowed blade, negative-bowed blade, forward-swept blade, afterward-swept blade, forward-skewed blade, afterward-skewed blade, forward-swept positive-bowed blade and afterward-skewed positive-bowed blade. Through the comparison of different three dimensional design blades on pressure distribution in spanwise and surface pressure distribution, limiting streamlines on suction surface, the effects of different kinds of blade on flow behavior is studied. Positive-bowed blade, forward-swept blade, after-skewed blade, forward-swept positive-bowed blade and afterward-skewed positive-bowed blade increase the pressure gradient at the corner between suction surface and shroud, push low energy fluid to mainstream, reduce low energy fluid accumulation at the corner, control separation flow. Meanwhile, the cases above increase the load of blade near the leading edge, reduce the probability of separation flow. Negative-bowed blade, afterward-swept blade and forward-skewed blade do it oppositely. They lead to the accumulation of low energy fluid at corner, reduce the load of blade near the leading edge, make the point where separation starts move forward and separation scale increase.

Key words: centrifuge;fan;bowed-blade;swept-blade