Numerical Investigation of Performance Improvement of a Modified Centrifugal Compressor with second Splitter and Vaned Diffuser

The performance of a centrifugal compressor for the turbocharger device is heavily affected by impeller design due to the flow dynamics in the impeller. Furthermore, modification and improvement of a centrifugal impeller is a challenging task for turbomachinery engineers .Hence, this study is aimed to further increase the compressor performance by introducing extra splitters in the impeller design. A series of impellers, having vaned diffuser stage was used for the performance evaluation of different configurations. A commercial CFD code, was used to simulate the flow and the primary grid generation. The influence of vaned diffuser meridional outlet section with a different width ratio of the modified centrifugal compressor has been studied by comparing the compressor stage and impeller performance at different width ratio. The comparative study of these results indicated noticeable compressor stage performance differences between the conventional and modified types. The results showed that the fluid dynamics within the modified compressor has indicated that the pressure ratio and volume flow rate were increased. Obviously, it was observed that the efficiency was increased and both the total pressure ratio and static pressure for 0.5 width ratio are increased. Overall, the numerical results obtained from CFD simulation could produce a highly reliable compared with experimental results for estimation on the performance and efficiency of the modified centrifugal compressor.