Abstract: Based on the couple stress fluid theory and the modified Elrod’s cavitation algorithm, the lubrication performance of dynamically-loaded journal bearings is numerically simulated. With the mass conserving boundary condition ,the Reynolds equation under dynamic loads is solved. Comparisons are made between the average inflow and the average leak flow. The results show that the average inflow and average leak flow based on the mass conserving boundary condition are equal, which is more agreeable with the fact. Comparisons are made between the Newtonian fluids and couple stress fluids for the effects on the oil film pressure, the minimum oil film thickness and the leak flow. It can be found that the couple stress fluids yield an obvious increase in the oil film thickness and the load capacity, but a decrease in the oil film pressure and the leak flow.

Key words: Cavitation, Couple stress fluids, Dynamically loaded journal bearing, Mass conserving boundary condition, Deformation measurement, Inherent deformation, Inverse analysis, Welding deformation