The aerodynamic performance of fans is significantly influenced by the inlet guide vane(IGV). Based on the experimental results of aerodynamic performance of a centrifugal fan with IGV

two improvement methods are proposed

i.e.

the dual linear segment of the airfoil shape replace original one and the increment of cascade solidity at small radius

to improve the IGV performance. The flowfields downstream of the improved IGV were measured with a five-hole probe. The measurement results indicate that the resistance coefficient of the improved IGV with the dual linear segment of the airfoil shape is smaller than that of the original one at the same vane angle while the prerotation coefficient of the improved IGV is larger than that of the original one. The optimal intersection angle of the dual linear segment is about 20°. Moreover

the prerotation coefficient of the improved IGV with larger blade solidity is obviously greater than that of the original one while the resistance coefficient is almost the same. In addition

the increased prerotation coefficient can be helpful to the extended modulation ability and energy saving of the IGV. For the centrifugal fan tested

the energy consumption decreases by about 2%-3% at the same flowrate of the fan when the vane angle of IGV is between 50° to 90°. It is possible that the function of the prerotation coefficient vs. the resistance coefficient could represent aerodynamic performance of IGV more effectively than the function of the prerotation coefficient vs. the vane angle

which could eliminate the influence by the difference position for zero vane angle.