Thermohydrodynamic lubrication analysis for a dynamically loaded journal bearing
Résumé
A numerical procedure is developed to analyse the ‘three-dimensional transient thermohydrodynamic (THD)’ behaviour of bearings under dynamic loading. The Reynolds equation, the three-dimensional energy equation in film, and the three-dimensional heat transfer equation in solids are simultaneously solved using a Newton-Raphson procedure and finite-element modelling to resolve the three-dimensional THD problem. The three-dimensional finite-element meshes of the three domains are interconnected and, therefore, the heat flux continuity conditions become implicit. The developed numerical procedure incorporates a cavitation (mass conservation) algorithm on the basis of the JFO (Jacobson, Floberg, and Olsson) model, which automatically predicts film rupture and reformation in the bearings. In order to validate the three-dimensional model, the temperature fields are compared with the temperature fields obtained with a numerical two-dimensional THD model with a parabolic pressure in the axial direction and also with experimental results. Finally, this model is applied to a bearing under sinusoidal loading in which the oil supply is fixed on the housing.