A Mixed-TEHD Model for Journal-Bearing Conformal Contacts—Part I: Model Formulation and Approximation of Heat Transfer Considering Asperity Contact

A mixed-TEHD (thermal elastohydrodynamic) model was developed for journal bearings working at large eccentricity ratios in order to facilitate a better understanding of mixed-lubrication phenomena for conformal-contact elements. The model consists of a mixed-lubrication process that considers the roughness effect and asperity contact, a thermal process for temperature analyses, and a thermal-elastic process for deformation calculations. In this model, the interactive journal, lubricant, and bearing were treated as an integrated system. Finite-element, finite-difference, and influence-function methods were utilized in the numerical process. The overall solution was achieved by the iteration method. Analyses of a simulated bearing-lubricant-journal system working under mixed-lubrication conditions were conducted, and the influence of the changes of lubricant flows as a result of the asperity contact on the system heat transfer and temperature distributions was numerically investigated.