Efficient computational modelling of low loaded bearings of turbocharger rotors

摘要

The overall efficiency of turbochargers is a strictly monitored variable in all applications. Increasing the overall efficiency is closely related to the mechanical efficiency and hence the rotor bearing system. This paper presents a new computational model describing the behaviour of the thrust bearings of the turbocharger rotor under different operating conditions. The model assumes steady state turbulent flow of lubricant through a thin lubrication gap in the form of a two-phase fluid. Fluid flow is affected by centrifugal forces due to high rotor speeds and by the change in lubricant properties due to pressure, temperature and shear rate. The model is designed to allow a very fast and efficient steady state solution for many input parameter variations, while maintaining a sustainable physical depth of description of the reality. The new computational model is confronted with three-dimensional higher-level models and verified by technical experiments on a real combustion engine turbocharger.