Experimental Methodology to Characterize Mechanical Losses in Small Turbochargers

Turbocharging and turbocharger phenomena have been studied by many authors covering a wide range of subjects. One of these subjects, and objective of this work, is mechanical losses due to friction. Current work presents a methodology to characterize mechanical losses in small size turbochargers. Such methodology is based on low and constant operating temperature values for the turbine, lubricating oil, and compressor. In this way, a quasi-adiabatic operation of the turbocharger is achieved which allows separating friction power from heat transfer. The experiments performed have covered variations in turbocharger speed, lubricating oil pressure and temperature. Heat flows between turbine and compressor has been maintained as reduced as possible by means of the experiment conditions. The results obtained show satisfactory correlation between mechanical efficiency of the studied turbocharger and non-dimensional magnitudes.Copyright © 2010 by ASME