Donghai Jin

Theory of Compressor Stability Enhancement Using Novel Casing Treatment, Part II: Experiment

A stall precursor-suppressed casing treatment is designed to enhance stall margin for both subsonic and transonic compressors. It is noted that the open area ratio of the stall precursor-suppressed casing treatment is only 4–10%, far smaller than conventional casing treatments, with over 50% open area ratio. The effect of the novel casing treatment on the stall margin and efficiency of compressors has been investigated experimentally. The results show that the stall precursor-suppressed casing treatment can improve the stall margin by about 8–18% without significantly decreasing the efficiency of the related fan/compressors. Meanwhile, the present investigation has also attempted to reveal the mechanism of stall margin improvement with such casing treatment. It is found that the stall precursor-suppressed casing treatment will delay the nonlinear development of the stall process by suppressing the propagation of the stall precursor waves, as compared with the evolution of the precursors without casing tre...

Effects of Rotating Inlet Distortion on Compressor Stability With Stall Precursor-Suppressed Casing Treatment

This paper conducts an experimental research of rotating inlet distortion on a low-speed large size test compressor with emphasis on the stability problem of axial fan/compressors, and the stall margin enhancement with a kind of stall precursor-suppressed (SPS) casing treatment. Some results on compressor stall margin and prestall behavior under the restriction of rotating inlet distortion are presented. The experimental results show that whether the inlet distortion is co-rotating or counter-rotating, the SPS casing treatment can still improve the stall margin without leading to additional efficiency loss caused by such configuration. The experiment results also show that the mechanism of the stall margin improvement with such casing treatment is associated with delaying the nonlinear development of the stall precursor waves and weakening the unsteady flow disturbances in a compression system.