Thermo-Hydrodynamic Analysis of Rough Journal Bearing

Temperature rise in modern hydrodynamic bearings reaches so high values and none of the engineering surface is perfectly smooth, therefore, the results obtained from the solution of Reynolds equation alone doesn’t give a true picture of the bearing behavior. In this work, the Reynolds equation is solved iteratively with the energy and heat transfer equations using finite difference technique and some roughness patterns have been assumed for the inner surface of the bearing and the outer surface of the journal to assess their effects on the bearing performance characteristics. A comparison between the behavior of smooth and rough bearings has been conducted. It is found that the presence of roughness asperities has a considerable influence on the bearing performance characteristics. The most important conclusions are that, roughness effects are more pronounced at higher values of eccentricity ratio and the effect of transverse roughness is to increase the load capacity, whereas longitudinal roughness causes a decrease in load as compared to a smooth bearing.