Effects of Bowed Stator on a Fan Characteristic With Distorted Inlet

Abstract

The adverse impacts of inlet distortion on fan/compressor have been recognized as an important problem for several decades. But it is still a topic of considerable interest. Prior work has proved, in distorted flow field, bowed stators can constrain separation and reduce flow loss. Different bow patterns and angles influence the fan/compressor in different way. But the above work was carried out only at the design point. How bowed stators influence the fan/compressor performance and stability at other operating conditions is still not clearly studied. Therefore, a deeper research work is required. In this paper, a time-dependent three-dimensional Reynolds averaged Navier-Stokes equation composed in “Fluent Software Pack” is carried out in a parallel supercomputer. A fan with straight/30° bowed stators is simulated with a clean/distorted inlet boundary condition at different operating conditions to obtain the fan characteristic. Two main aspects are contained in this paper. The first is about the effects of straight/bowed stators on the fan characteristics with clean and distorted inlet at different operating point. It is found that 30° bowed stator will worsen the fan performance at most operating conditions with clean inlet. But, when inlet is distorted, it can improve the fan performance and increase the stall margin obviously. The effects of bowed stators on the fan performance and flow field at near stall and design point are analyzed secondly. The fan stability and the anti-distortion capability can be improved by using bowed stator when the inlet total pressure is non-uniform.