摘要
To systematically analyze the complete transient behavior of gas foil radial bearings from start-up to steady state, this study develops an efficient simulation framework that integrates a pre-computed static computational fluid dynamics database. Unlike conventional approaches that focus solely on steady-state or single-speed operating conditions, the proposed method employs a step-wise numerical scheme to track the shaft trajectory inside the bearing hole. The supporting force, frictional force, and attitude angle of the shaft are continuously updated in real time, enabling accurate reproduction of the transition from the contact regime to the thin-film lubrication regime. The core of the simulation relies on a lookup-table mechanism. A computational fluid dynamics-based database of supporting forces under various shaft speeds and attitude angles is generated in advance, and queried dynamically during simulation to update the bearing force response and operating condition. This approach significantly reduces computational cost while maintaining the physical fidelity and transparency of the underlying model. The frictional resistance at the shaft surface is evaluated according to the minimum gas film thickness, ensuring that contact interactions between the shaft and the bearing are properly accounted for. The simulation framework supports analysis under arbitrary start-up speeds and outputs comprehensive dynamic information, including shaft center trajectories, impact locations of the shaft, supporting force evolution, and attitude-angle variation. It is therefore suitable for preliminary dynamic assessment following the completion of bearing design. Compared with full three-dimensional fluid-structure interaction simulations, the proposed method offers higher computational efficiency and enhanced physical interpretability. It also serves as a bridge between theoretical bearing design and early-stage engineering evaluation, allowing designers to visualize the shaft behavior during acceleration and stabilization, and to rapidly assess the bearing’s load-carrying capability. Overall, the proposed simulation architecture fills a gap in the literature regarding start-up-to-steady-state analysis of gas foil bearings, and provides a reproducible, reviewable, and engineering-practical tool for dynamic performance evaluation. The method shows strong potential for future application in high-speed micro-turbomachinery bearing design and verification. © 2026, Avestia Publishing. All rights reserved.