Two-phase flow characteristics in dual-rotor support bearing chamber of aero-engines and sensitivity analysis

Driven by the demand for lightweight aero-engines, the dual-rotor support bearing chamber contributes significantly to reducing lubrication system costs and promoting design innovation. Maintaining optimal oil-air flow within the chamber is essential for effective thermal management and lubrication system reliability. This study investigates the two-phase medium flow characteristics in the dual-support bearing chamber. Key parameters influencing flow behavior and their interactions were evaluated using a Back Propagation (BP) neural network combined with Sobol’ sensitivity analysis. The results show that the migration of vortex structures caused by inter-shaft interference is an important factor affecting changes in oil flow behavior. At T_oil = 303.15 K, increasing the counter-rotating speed enhances this interference, resulting in a 112.42% increase in oil flow velocity. The oil flow rate has a limited effect on vortex migration, while increasing the oil supply temperature leads to higher oil residence mass and flow velocity within the chamber. Sensitivity analysis further reveals that oil residence mass is mainly influenced by oil flow rate, while shaft speed mainly governs oil flow velocity, with their interactions significantly affecting two-phase flow behavior. The coupling effects of operating parameters should be thoroughly considered during the design process.