Heat Transfer Analysis in a Turbocharger Turbine: an Experimental and Computational Evaluation

This paper presents the performance of a turbocharger under non-adiabatic conditions in order to assess the impact of heat transfer. A commercial turbocharger was installed on a 2.0 liter diesel engine and measurements were conducted for a range of engine speeds and loads. The test results enabled to assess the impact of the engine on the temperature distribution of the bodies constituting the turbocharger, quantify the heat fluxes through the turbocharger and evaluate their effects on the deterioration of compressor performance. A 1-D heat transfer model was also developed and validated against the experimental measurements. The algorithms calculate the heat transferred through the turbocharger by means of lump capacitances. Compressor maps were then generated for a range of speeds and temperatures of the exhaust gases at the inlet to turbine and the efficiency drop associated with heat transfer was quantified. Based on the data generated by the model, a new correlation for the compressor non-adiabatic efficiency was found by means of a multiple regression analysis; the work is based on a statistical description of the different parameters that affect the heat transfer model.