Effects of Starved Lubrication on the Stability of Flexible Rotor Systems Supported by Journal Bearing: Parametric Study Using the HB-AFT Method

Abstract Journal bearings are widely used in rotating machinery due to their strong damping properties. Recently, the idea of operating journal bearings under starved lubrication conditions to reduce energy loss has attracted attention. However, this condition introduces complex nonlinear behaviors that can affect the stability of the system. In this study, periodic vibration of a flexible rotor system supported by a circular journal bearing under starved conditions was analyzed using the harmonic balance method in an alternating frequency-time domain (HB-AFT). The stability of the obtained solutions was evaluated under flooded and starved lubrication conditions. The results showed that although starvation did sometimes destabilize the system under the experimental parameters, the results of a parameter study indicated that specific design choices such as larger clearances or optimized oil supply angles can expand the stable operating region.