Steady Sate Performance Analysis of Non-Circular 3-Lobe Hydrodynamic Journal Bearing with Couple Stress Lubricant

In this research steady static performance characteristics of 3-lobe noncircular journal bearings with couple stress fluids are presented. Lubricating oil containing additives and contaminants is modeled as couple stress fluid. The modified Reynolds equation is obtained using the couple stress lubrication theory and solving it by using finite element method (FEM) as a simple and efficient numerical technique. The steady state performance characteristics in terms of load carrying capacity, coefficient of friction, side leakage flow and attitude angle are determined for various values of couple stress lubricant characteristic parameter. The results show compared with Newtonian fluids, that couple stress fluid exhibits better efficiency. Also results show that couple stress fluids exhibit increase in load carrying capacity but decrease in coefficient of friction, attitude angle and side leakage flow. It is observed that the effect of lubricant type is more pronounced at high couple stress parameter. Results show that though noncircularity of journal bearings can have certain advantages in bearing operation, however, the magnitude of fluid film pressure distribution developed in hydrodynamic 3-lobe bearings decreases with increasing in noncircularity or decreasing of preload factor in bearing.

Keywords:

Couple Stress Fluid , 3-Lobe Journal Bearing , Hydrodynamic Lubrication , Static Performance , FEM