ANALYTICAL LOSS PREDICTION FOR TURBOCHARGER COMPRESSORS

A tool for performance prediction of automotive turbocharger centrifugal compressors is presented. The code is based on analytical models from literature and includes vaneless compressor inlet, impeller, vaneless diffuser and a volute. The impeller exit flow is modelled using a modified two-zone approach which accounts for the interaction of aerodynamic blockage and diffusion. Thermal and pressure losses inside the impeller are computed using different collections of loss models from open literature. The data are used to evaluate the percentage of individual loss mechanisms on the overall losses. The predicted performance is compared with highly resolved numerical simulations and experiments. A correlation for the minimal boundary of the aerodynamic blockage coefficient at different operating points is derived from the numerical results which serves as input to the analytical model.