Performance Analysis and Improvement of a Centrifugal Compressor Based on Partial Similarity Principle

In this paper, with the help of partial similarity principle, aerodynamic performance of a centrifugal compressor in a turbocharger unit is analyzed and improved based on a low-speed large-scaled model. In order to achieve flow similarity between the scaled compressor and the prototype, tip clearance and diffuser outlet diameter have been modified further. It is observed from the numerical results that the relative error between the scaled compressor and the prototype is less than 0.8%. It means that the flow field of the scaled compressor is similar to the prototype though the Reynolds number is neglected during the scaling process. Furthermore, the large-scaled impeller has been improved by analyzing the numerical results, and then, the improved impeller is scaled down back to the smaller one by using the partial similarity principle, which geometric dimensions have the same level as those of the prototype but performance is improved obviously. Meanwhile, the experiment results are used to validate the method.