Centrifugal compressors with high aerodynamic performance are widely used in turbochargers, aero-engines and petrochemical engineering. The impeller is the core component and plays a key role in determining the compressor performance.
This paper reports the optimisation of the aerodynamic performance of an industrial centrifugal impeller by a multi-objective evolutionary strategy. Firstly the 3-D modeling method for parameterisation of impeller’s geometry was described. Secondly the traditional NSGA-II method was modified to improve its ability and efficiency. Employed CFD code was first validated using the experimental data of an existing impeller. The optimisation was applied to the industrial centrifugal impeller through a two-step optimization process to allow for significant variations of the impeller geometry and speedy finding of the optimum. The optimisation was completed within 53 hours on a workstation with two 24-core processors (Xeon(R) E5-2670 v3 2.3GHz). The results indicated that the isentropic efficiency of the impeller increased by 5.3 percents and the total pressure ratio by 20.5 percents at design condition.