The effect of axial geometrical variations on the steady state characteristics of oil lubricated journal bearings using titanium dioxide nanoparticles as lubricant additives

The current work examines journal bearings with axial geometrical configurations that are lubricated with nanofluids. Because of recent advancements in numerically controlled machine tools, accurate machining of complex shapes is now a realistic operation. A theoretical prediction of bearing characteristics for different complicated geometries with varying bearing length to shaft diameter ratios at varying eccentricity ratios is required prior to any experimental effort. The Reynolds like equation that governs the pressure distribution inside the bearing is provided. Four various bearing geometries with conical (wedge), concave, convex, and wavy surfaces are chosen to investigate the bearing characteristics while taking into account the impact of increasing nanoparticle concentrations and aggregate particle sizes. The modified Krieger-Dougherty viscosity model was used to investigate the influence of TiO₂ nanoparticle lubricant additives on the performance of the chosen journal bearings. The results show that the chosen shapes improve the bearing's performance over the plain cylindrical bearing. The concave design is also shown to be better than the others; however the findings show that an optimization method may be required to acquire the geometry that provides the optimum bearing characteristics.