Experimental static thermal performance analysis of nanolubricants based elliptical journal bearings

Abstract

The growing demands of high-speed rotary systems require journal bearings with enhanced tribological performance. Conventional lubricants consistently fall short, so nanolubricants-upgraded with nanoparticles are a viable alternative due to high thermal conductivity and load-carrying capacity. This article presents an extensive experimental investigation on elliptical journal bearing performance utilizing a journal bearing test rig with a variety of operating oils, speed and load parameters. Two base lubricants and nanolubricants synthesized by dispersing titanium dioxide (TiO₂) and copper oxide (CuO) nanoparticles at three concentrations (0.5%, 1.0%, and 2.0% by weight) have been studied. Two important performance parameters, namely, hydrodynamic pressure distribution and oil film temperature have been evaluated under steady-state conditions. The results reveal that nanolubricants significantly enhance the static thermal bearing performance with all operating parameters. Specifically, nanolubricants prepared by blending TiO₂ gave better results in comparison to CuO based nanolubricants with marked increase in hydrodynamic pressure (up to 15.67%) with insignificant rise (up to 3.83%) in oil temperature. Bearing performance has been further improved with increase in nanoparticles concentration. In addition, elliptical bearings also had preferred pressure contours compared with conventional circular bearings, which reveals their possible suitability under high-load bearing applications. The findings reveal the potential of nanolubricants and elliptical bearing geometries for increasing the reliability and performance of modern tribosystems.