Rotor-dynamic analysis of electro-rheological lubricant operated textured surface two-lobe hydrodynamic journal bearing

Purpose This study aims to investigate effectiveness of surface texturing in improving steady-state and dynamic performance characteristics of two-lobe journal bearings using electrorheological (ER) lubricants. Design/methodology/approach The Reynolds equation is solved using finite element approach and Newton–Raphson method, with gaseous cavitation in lubricant addressed via a mass-conserving algorithm. The ER fluids constitute dielectric particles suspended in non-conductive oil. A continuous Bingham fluid model describes lubricant’s non-linear behavior. The study explored how dimple shape, surface texture configuration and applied electric field affect performance of two-lobe journal bearings. To assess the journal’s dynamic stability, equation of motion is solved using fourth-order Runge–Kutta method, predicting the journal’s center trajectory. Findings The findings reveal that applying ER lubricants and partial surface texturing in two-lobe journal bearings boosts direct stiffness by 1037.1% and damping by 46%. In addition, the threshold speed improves by 100.1%, and the bearings exhibit smaller, more stable linear motion trajectories and limit cycles. These results suggest that designers should consider using first-half textured surface two-lobe journal bearings operating with ER lubricants to enhance stability and performance under simulated conditions. Originality/value This study presents rotor-dynamic performance of textured surface two-lobe journal bearing operating with ER lubricant. Texture shape, attributes and configuration are determined to maximize direct stiffness coefficients and minimize the journal center motion trajectories. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2024-0458/