Numerical analysis and optimization of the volute in a centrifugal compressor

Abstract

Previous search works on centrifugal compressors mainly focused on the most important part, namely the impeller. However, as the potential of the impeller are exhausting, more and more attentions have been turned to the static parts, such as the diffuser and volute. Based on the three dimensional geometry of a typical prototype design of a centrifugal stage and volute, and commercial CFD software NUMECA, a numerical analytic system was developed in this paper. Detailed flow structures and main sources of the flow losses were analyzed and structural modifications were proposed and experimented numerically. Main factors affecting the performance were studied. Final results indicate that the polytropic efficiency can be increased by 4.5%. As the original design is typical and widely used in real production, it was estimated that the overall efficiency of the centrifugal compressor can be increased by 1.5-2% with this new design method.