Abstract:Many related researches on journal bearings are based on the case of constant viscosity,which is quite different from the actual work of journal bearings.Computational fluid dynamics (CFD) FLUENT was used to calculate the viscosity of lubricating oil of hybrid bearing by UDF program of viscositytemperature equation,and the effects of viscositytemperature effect on the performance of hybrid bearing were analyzed.The oil film pressure and bearing capacity,the axial and circumferential temperature distribution of the oil film were compared under the conditions of constant viscosity and variable viscosity.The results show that under the condition of considering the viscositytemperature effect,the bearing capacity,oil film pressure and friction are less than those under the constant viscosity condition.This is because that the decrease of viscosity due to temperature increase causes the decrease of static pressure and bearing capacity of oil film.In the axial direction of the bearing,the temperature of the oil film is increased gradually from the center of the oil film to the two ends.In the circumferential direction of the bearing,the oil film temperature is increased first and then decreased from the convergence area to the divergence area,and the peak value of the oil film temperature appears at the end of the divergence area of the bearing.