A Comparison of Performance Predictions between 1D Models and Numerical Data for a Turbocharger Compressor

Compressor performance prediction models, based on integral conservation of mass, momentum and energy with empirical loss terms, are important tools in early design stages. Two such models from literature are compared to numerical results for an automotive turbocharger radial compressor with a vaneless diffuser and a volute. Results show that these models are less accurate than fully three-dimensional numerical RANS CFD calculations at low impeller speeds and choke, but can compete at high impeller speeds. Of the two impeller models, one gives a more accurate prediction than the other. The diffuser and volute models investigated here show large differences to the CFD calculations at off-design conditions. A comparison of the impeller loss terms to CFD entropy increase indicates also possibilities for improvement in the impeller models.