Sensitivity of Texture Evolution and Performance to Eccentricity, Misalignment, and Oil Supply in Journal Bearings with the Circumferential Oil Groove: An Adjoint-Based Optimization Study

Previous studies on improving journal bearing performance have predominantly overlooked the combined effects of the surface textures, circumferential oil grooves, eccentricity ratio, and misalignment. To address this gap, this study employed an adjoint -based optimization framework to optimize the LCC (load-carrying capacity) of journal bearings based on the mixed lubrication model. By incorporating the influence of the circumferential oil groove, the influences of the oil supply pressure, eccentricity ratio, and misalignment angle on the bearing performance and optimal texture evolution were studied. The results show that increased inlet oil pressure shortens textures and reduces the LCC enhancement, while misalignment boosts the absolute LCC but diminishes the relative benefit of textures. Bidirectionally optimized textures maintain robust performance under reverse rotation, with LCC improvements of 12.00 N at an eccentricity ratio (ER) of 0.8. In contrast, unidirectional textures may impair performance, with a reduction of up to –19.53 N. It is recommended to employ symmetric textures for bidirectional operation and to limit misalignment in order to retain the benefits of surface texturing. This research provides a practical foundation for designing high-performance journal bearings.