Turbocharger turbine aerodynamic optimization for reduced fuel consumption and CO₂ emissions from heavy-duty diesel engines: Experimental validation and flow field analysis

This paper describes aerodynamic optimization of the high pressure turbine in a two-stage heavy-duty diesel engine air system. A genetic algorithm generates designs that reduce fuel consumption and CO₂ emissions by maximizing turbine efficiency, while meeting boost and packaging requirements. Scaling the baseline 47 mm diameter turbine to 83.6 mm permits on-design testing. Optimization of the scaled baseline predicts a 2.1%-point on-design benefit, confirmed by experiments which measure a 2.6%-point efficiency gain. This validates both the CFD model and the optimization process. CFD flow field analysis reveals the aerodynamic loss in the blade tip region is significantly improved by the optimized design.