In the event of air flow passing the airfoil in G4-73 centrifugal fans used in power plants

the flow rate is low

and the Reynolds number is quite different from that of the aviation airfoil

then the location of stall is also different

therefore

it is necessary to study the airfoil stall bahavior in said centrifugal fans.The gird near airfoil has been partially concentrated

the flow movement under different impluse angle of air flow being numerically simulated by using FLUENT software.It has discovered that the airfoil stall is occurred on the non-working sorface.Through analysis of the relationship between impluse angle and separated locations

as well as the flow movement in the stall regions

it is obtained that the impulse angle under the studied condition should be less than-20° for ensuring safe operation of the air fan

the swirl located on suction surface X/C=0.5 is the strongest

and this swirl will endanger safe operation of the air fan.