Analysis on oil film characteristics of turbocharger bearing based ontwo-phase flow

The static characteristics of inner oil film of turbocharger semi-floating ring bearing were calculated by CFD method. For the inner oil film with axial through grooves, the distribution of oil film pressure and air-phase volume fraction were predicted considering the influence of two-phase flow cavitation and non-Newton fluid. The change rules of oil film bearing capacity and friction power losses with the journal speeds, eccentricity ratio, oil temperature and pressure were also evaluated respectively. The results showed that the uppermost impact factors to friction power losses were oil temperature and journal speed, while the rare relationship with the position of through axial grooves and the cavitation at the negative pressure zone was also found. The oil film bearing capacity can be improved by increasing the eccentricity ratio and oil pressure, or cooling the oil temperature. However, the law of variation with speed up was not consistent. Simultaneously, it was beneficial for alleviating air-phase volume fraction to reduce the eccentricity ratio and oil temperature, or raise the oil pressure.