Abstract:For the thermohydrodynamic characteristics of journal bearings,a threedimensional thermal coupling model of bearingrotor considering cavitation effect and viscositytemperature effect was established.The heat conduction equation of journal and bearing bush,oil film energy equation and full cavitation model were solved.The calculation results indicate that the maximum temperature of the lower bearing bush is located in downstream of the minimum film thickness.The temperature of the lower bearing bushis increased gradually along the direction of lubricating oil flow,while the temperature of the upper bearing bush changes less.Considering the bearing heat conduction and twophase flow characteristics, the thermal coupling model is more practical than the adiabatic boundary model.Compared with adiabatic boundary model,the pressure distribution trend of this model is the same,but the calculated pressure is bigger.With the increase of inlet oil temperature,oil film maximum pressure,bearing capacity,cavitation volume ratio,temperature difference between inlet and outlet are decreased,and the deviation between the thermal coupling model and the adiabatic boundary model is reduced.The temperature distribution in the convergent zone and the divergent zone calculated by the threedimensional thermal coupled model are in agreement with the experimental data,which verifies the threedimensional thermal coupled model.