Adaptive flow optimization of a turbocharger compressor to improve engine low speed performance

To improve the engine overall performance, an adaptive flow optimization procedure is proposed in this paper to synthesize turbocharger compressor optimum designs. Two objective functions are involved in the adaptive optimization. They are the traditional compressor design and the compressor design with consideration of improving engine overall performance. The two-step decomposition approach is chosen to generate optimum designs. The optimized designs not only satisfy turbomachinery and engine constraints but also have optimum objective function values in the two fields. Performance sensitivity analysis of compressor main design variables is performed for the flow optimization design process. A centrifugal compressor is redesigned for a turbocharged gasoline engine, as an example, based on the adaptive flow optimization process. The calculating results show a more than 5% increase of isentropic efficiency in comparison with the base line compressor, resulting in a more than 19% increase of engine torque at low speed conditions.