Prediction model for mechanical losses generated in turbocharger bearings considering frictional heat

Accurate prediction of mechanical losses in turbocharger bearings is necessary for efficient automotive energy management. In this study, a lumped model was developed to consider the frictional heat produced by the rapid rotation of the shaft. It is assumed that frictional heat causes the lubricating oil in contact with the journal, journal bearing, and housing to rise. The model uses the energy equation to calculate the temperature distribution of lubricating oil in the journal bearing gap. The trends in the mechanical losses from the prediction model are consistent with the experimental values obtained using the retardation method.