Enhancement of Steady-state Performance of Hydrodynamic Journal Bearings Using Macro-groove Textures with Lubricant Additives

The present study investigates numerically the steady-state performance of macro-grooved hydrodynamic journal bearings (MGHJB) with rectangular-shaped macro-grooves in different bearing surface regions, such as the full, first, second, and pressure-increasing regions. The steady-state parameters like load carrying capacity (LCC) and friction coefficient (FC) are calculated using the finite element approach by solving the governing Reynolds’s equation of lubricant flow. The effect of rectangular macro-grooves provided in the specific regions of the journal bearing, along with the variation of groove depth and the area density, is considered for investigation at different eccentricity ratios. From the simulated results, the steady-state parameters of the journal bearing are enhanced from lower to higher eccentricity ratios. The maximum enhancement of LCC is 95.75% and reduction in friction coefficient (FC) is 48.67% found at the lower eccentricity ratio of 0.2 when four rectangular-shaped macro-grooves are provided in the pressure-increasing region at a groove depth of 0.9 and an area density of 58.50%. Furthermore, with the inclusion of 0.5% weight fractions of copper oxide and cerium oxide in the lubricant at 90°C, the steady-state performance of the bearing is further enhanced.