Numerical Analysis of the Internal Flow Field of a Marine Centrifugal Compressor and the Structural Optimization of a Vaned Diffuser

Due to coupling effect and interaction between the impeller and diffuser, internal flow field of a centrifugal compressor is very complicated. In the present thesis, numerical analysis of the internal flow field of a marine centrifugal compressor in multistage environment was carried out. The results indicate that narrow working rang and low efficiency of the prototypical compressor contributes to the eddy between outlet of the impeller and inlet of the diffuser. The coupling relationship between the impeller and diffuser was improved by reducing vane number of the diffuser and shortening the length of the blade trailing edge. The optimal results show that the stable working range of the compressor was broadened and working efficiency and pressure ratio in multistage environment were increased significantly.