Aerodynamic Design Optimization of a Micro Radial Compressor of a Turbocharger

This study presents an aerodynamic design optimization of a micro radial compressor impeller on a turbocharger used in a 0.8 L two-cylinder gasoline engine. In the conventional design optimization of the impeller, the hub and shroud curve of the main blade is commonly parameterized with a beta distribution, and splitter blades are generally considered short versions of the full blade. However, geometrical parameterizations in our study mainly focus on the beta distribution of a full blade, and it is parameterized differently from the conventional way. Eight parameters are selected as design variables for the beta distribution. To maximize the isentropic efficiency, design points that are created by Design of Experiment (DOE) are evaluated through single-objective optimization coupled with a non-parametric regression surrogate model. Furthermore, the splitter leading edge location on the meridional plane is investigated to enhance the performance of the impeller after the optimization process. The results show that total efficiency enhancement of approximately 2.2% is achieved. Furthermore, the findings show that a full blade beta distribution and the splitter leading edge location are sufficient parameters to optimize the impeller, and, with the proposed optimization, splitter blades are no longer copies of the full blade for each application.