A Parametric Study for Finite-Width Journal Bearings Operating in the Turbulent Thermohydrodynamic Regime

• Main Authors: Wei-Zen Lee, 李維仁
• Other Authors: Sheng-Jii Hsieh
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/11004812771410781505

碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 92 === 　　For the design of bearing system, it is important to have an accurate estimation of the load capacity, friction force, eccentricity angle, and side leakage. It is found from the literature that the parametric studies of hydrodynamic journal bearings have been made in laminar isothermal, laminar thermohydrodynamic (THD), and turbulent isothermal regimes. For turbulent THD bearings, the parameter studies have not been in a completed status. The objectives of this study are to use a general fluid-film lubrication model to analyze finite-width journal bearings operating in turbulent isothermal and turbulent THD regimes, and to establish the formulations for the performance parameters. 　　The analysis model used in this study combines the Legendre collocation method, bulk-flow model, and Elrod’s cavitation model. This model considers turbulence, THD, and cavitation effects. The results show that the load capacity and the side leakage increases with the eccentricity ratio, but the eccentricity angle decreases as the eccentricity ratio increases. When bearing width increases, the load capacity will increase but the side leakage will decrease. When the mean Reynolds number increases, the load capacity and friction force will increase significantly, but the eccentricity angle increases slightly. The THD effects significantly decrease the load capacity and friction force, yet increase the eccentricity angle. The formulations for the performance parameters were found using the least-squares method. With the equations provided, designers can quickly calculate the parameter using a calculator.