Comparative analysis of herringbone groove patterns in gas foil journal bearings: Static and dynamic performance evaluation

Gas foil journal bearings (GFJBs) are critical components in high-speed turbomachinery due to their advantages such as increased load capacity, reduced friction, and improved rotordynamic stability. This study presents a comprehensive numerical analysis comparing the static and dynamic performance of herringbone groove textures—namely single, double, and multi-structured patterns—applied to the top foil of GFJBs. The pressure distribution is obtained by solving the Reynolds equation using the finite difference method, and key performance metrics such as load-carrying capacity, frictional torque, power loss, effective stiffness, damping, and system stability are systematically evaluated. Among the patterns, the multi-herringbone texture (Texture 3) consistently outperformed other configurations. To further enhance performance, a multi-objective Particle Swarm Optimization (PSO) algorithm was employed to optimize key groove parameters. The optimized configuration yielded improved static and dynamic behavior, including higher stiffness and damping values and enhanced system stability. Notably, the optimized textured GFJB demonstrated a 26.9% increase in load-carrying capacity (LCC) compared to the plain GFJB. This research highlights the effectiveness of surface textures in enhancing GFJB performance and demonstrates the utility of PSO as a powerful tool for multi-objective optimization in high-speed bearing design.