Effects of design parameters on performance of noncircular journal bearings lubricated with micropolar fluid

In this work generalized differential quadrature (GDQ) method as a simple, efficient and high order numerical technique is used for the solution of modified Reynolds equation to obtain the performance of micropolar lubricated hydrodynamic circular and noncircular lobed journal bearings. Effects of various parameters, namely the nondimensional micropolar characteristic length, coupling number, preload factor, mount angle andeccentricity ratio on the performance parameters of bearings have been investigated. The computed results show that depending on the characteristic length and the coupling number, there will be significant changes on the performance parameters. The results show, compared with Newtonian fluids, that micropolar fluids exhibit increase in load carrying capacity but decrease in coefficient of friction, attitude angle and side leakage flow. Also it is observed that the effect of micropolar fluids is more pronounced at high coupling numbers. It is observed from the results that though noncircularity of journal bearings can have certain advantages in bearing operation, however, the magnitude of pressure distribution developed in bearings decreases with increasing in noncircularity or decreasing of preload factor in bearing. Decrease in magnitude of pressurecauses a decrease in load carrying capacity, attitude angle but increase in coefficient of friction in bearings. Also results show that the variation of mount angle can has variable effects on journal bearing performance parameters. Among the two types of bearings considered, the effect of the mount angle is more significant for two lobe bearings in comparison to three lobe bearings.

کلیدواژه ها:

noncircular journal bearing ، hydrodynamic lubrication ، micropolar fluid ، mount angle ، GDQmethod