Design and Experiment of Casing Treatment for a Centrifugal Compressor

Abstract

Abstract Centrifugal compressors have been widely used in light-duty turboshaft engines and automotive turbochargers. One of the essential requirements for centrifugal compressors in these applications is to have adequate stable flow range. As the pressure ratio increases, the stable flow range drops dramatically, and this highlights the importance of stability improvement for centrifugal compressors. This paper first gives a brief review on the measures available for extending the stable flow range, and then focuses on the realization of self-recirculating casing treatment for a centrifugal compressor. The design principles of the casing treatment were introduced. Then the simulations were conducted to design and optimize the geometry of the casing treatment, and finally an optimum case was selected for experimental validation. The experiment results indicate that the designed casing treatment improve the stable flow range by about 5 percent at design speed, while keeping the efficiency almost identical.