Study of Simulated Distortion Waves in an Axial Flow Fan

Inflow distortion is a problem encountered during axial fan/compressor operation. There are a large number of experimental studies that have been carried out to study the distortion effects on the axial fan/compressor performance by using wire mesh screens, by blocking inlet passage and physically disturbing the inlet flow. When the compressor experiences off design operation, it is likely to experience an inlet distortion, which determines its operational sustainability. Every compressor in each flight segment undergoes non-uniform inlet flow fields and responds differently to that of a clean inlet flow, for which it is designed. To meet specific performance requirements, it is often required for a compressor to pass through off-design environments. Distortion, simulated as waves or combination of waves in propagation, have been studied in this work. It has been observed that the effect of distortion depends on types of waves applied, area covered by distortion, operating speed of the fan/compressor & location of the distortion waves with respect to blade profile. For a given velocity in distorted passages spike wave has more detrimental effect compare to normal distortion wave or a triangular wave. A few combination distortion waves have been studied too.