Lubrication performance of journal bearings with kite-shaped textures

The paper proposes a kite-shaped biomimetic surface texture to enhance the hydrodynamic lubrication performance of journal bearings under high-load and misaligned operating conditions. A numerical model is developed based on the mass-conservative Reynolds equation and incorporates surface roughness effects and cavitation described by the Jakobsson–Floberg–Olsson (JFO) condition. Mixed lubrication is accounted for using the Greenwood–Tripp asperity contact model, enabling coupled evaluation of pressure distribution, load capacity, and friction behaviour. The effects of texture distribution, axial coverage ratio, and arrangement pattern are systematically analyzed, together with the influences of eccentricity and journal misalignment under steady and transient conditions. Results show that lubrication performance strongly depends on texture placement relative to the convergent-divergent film region. Textures located in the divergent zone significantly enhance load-carrying capacity and reduce friction, whereas improper placement may degrade performance. Under dynamic loading and misalignment, the textured bearing exhibits improved stability, reduced friction power, and suppressed orbital fluctuations, particularly when textures are arranged downstream. Overall, appropriately designed kite-shaped textures provide an effective strategy for improving lubrication performance and reducing energy loss in journal bearings under complex operating conditions.