Purpose This study aims to investigate the impact of surface waviness on the static performance parameters of hydrodynamic journal bearings operating with lubricants containing copper oxide (CuO) and cerium oxide (CeO2) nanoparticles. Design/methodology/approach The static performance parameters of bearings with surface waviness and the addition of nanoparticles in lubricants were calculated using the nondimensional form of Reynolds equation and finite element method. Static performance parameters are calculated at different waviness numbers in the circumferential, axial and both directions at various wave amplitudes with variable viscosities of lubricants with nanoparticles using the viscosity equation forming a relationship between the relative viscosity, temperature and weight fraction of nanoparticles in lubricant developed from the experimental results. Findings The computed results indicate that the impact of waviness on the bearing surface enhances the load capacity, reduces friction coefficient, and is more effective in the circumferential direction than in the axial direction or in both directions. The addition of CuO and CeO2 to the lubricant enhanced its viscosity which further improved the steady-state parameters of the wave bearing. Research limitations/implications This study is based on a numerical technique, which has significant limitations, and the simulated results must be tested experimentally. Practical implications The current findings will be beneficial for designers to improve the performance of hydrodynamic journal bearings. Originality/value The calculated results demonstrate that the combined effect of the surface waviness on bearings and the addition of nanoparticles to lubricants can greatly increase the performance of hydrodynamic journal bearings.

In this paper, the static performance analysis of journal bearing having full and partial surface waviness has been presented. The surface waviness is to be considered in the full, first half, second half, and pressure-increasing and decreasing regions of the bearing for analysis. The effect of surface waviness is considered by modifying the lubricant flow governing Reynolds equation with the film thickness equation and it is solved with the finite element method to get performance parameters like bearing load capacity, friction coefficient, and so forth operating under eccentricity ratios range of 0.2-0.8. The waviness geometrical parameters like waviness numbers and amplitudes are also considered in circumferential, axial, and both directions in the selected regions. The maximum performance has been found for waviness in the full and pressureincreasing region in the circumferential direction at a high eccentricity ratio.