ABSTRACT
Heat transfer within turbochargers affects the measured turbocharger efficiency. Differences of actual and measured efficiency cause reduced accuracy in the matching process. A so-called thermal network representing the thermal behavior of the turbocharger consisting out of several thermal nodes is created based on geometric design data. The thermal network considers the thermal connectivity between the components and, therefore represents the thermal behavior of the turbocharger. It is validated by experiments utilizing data from various thermocouples applied to a turbocharger. Tests were done for different hot gas temperature ranges. A heat transfer model, named HTTR, combined with heat transfer effect corrected turbine and compressor maps integrated into the thermal network allows improved accuracy in engine simulation in all engine operating conditions even in cold start and transient states. This report shows the validation of the HTTR by comparing experimental results from hot gas test benches and calculation results utilizing GT-POWER. The accuracy of the temperature distribution in the turbocharger and the efficiency affected by heat transfer is verified by varying the turbine inlet temperature. Under steady state conditions the HTTR was confirmed.
