표면 거칠기 및 샤프트 기동 각가속도 변화에 따른 저널 베어링 마찰 진동 해석

Abstract

This study investigates the friction-induced vibration behavior of journal bearings during startup through numerical analysis, focusing on the impact of surface roughness and angular acceleration. Journal bearings are critical components of mechanical systems, and their transient dynamics during startup are particularly prone to frictional instabilities and vibrations. To model these phenomena, the average Reynolds equation is employed to describe the lubrication flow, whereas the GW(Greenwood and Williamson) model is used to account for the surface roughness effects at the contact interface. The numerical model integrates the average Reynolds equation with the GW model, enabling a detailed analysis of the hydrodynamic and contact phenomena in the mixed lubrication regime. Variations in the angular acceleration are also simulated to explore their influence on the dynamic behavior of the system. The results revealed that surface roughness significantly affected the lubrication regime, altering the vibration amplitudes, whereas angular acceleration contributed to complex dynamic responses during the startup phase. These findings underscore the importance of incorporating both hydrodynamic and contact mechanics models to accurately predict friction-induced vibrations under transient conditions. By providing a comprehensive understanding of the relationship between the operational parameters and dynamic responses, this study lays the foundation for optimizing journal bearing performance and reliability under variable startup conditions.