The centrifugal compressor in an automotive turbocharger is required to have a high
pressure ratio, high efficiency, and in particular, wide operating range. Performance improvement
has been carried out utilizing computational fluid dynamics and experiments, and further
performance improvement through conventional design methods has become increasingly difficult,
requiring a significant amount of time for aerodynamic design. Therefore, we developed an
optimized design method with computers using a genetic algorithm and artificial neural network in
place of the conventional design method. This method was applied to the design of the centrifugal
compressor impeller. The performance results of the two designed impellers attained higher
efficiency and a significant extension of operating range, respectively, compared with the baseline
impeller.