Application of a Novel Gaseous Cavitation Model for Hydrodynamic Bearings in Both 2D Reynolds and 3D Navier-Stokes Equations

Abstract

The 2D Reynolds equation is the traditional method used for solving hydrodynamic lubrication problems, whereas the full 3D Navier-Stokes (NS) equation has been a new and attractive approach in recent years. Unfortunately, the conventional cavitation models which were successful in Reynolds equation have encountered difficulties when they are implemented in NS equation, thus the proper modeling of cavitation has been a fundamental and important issue for the application of NS equation in bearing problems. A novel cavitation model was derived by the authors, which is based on the mechanism of the gaseous cavitation in submerged bearings. In this paper, this cavitation model is implemented in both 2D Reynolds and 3D NS equations. Different governing equations with various cavitation models are then used to analyze two typical oil-film bearings, i.e. a plain journal bearing and a pocketed thrust washer, so as to illustrate the advantage of the presented gaseous cavitation model. It is found that the gaseous model shows accurate prediction of the bearing overall performance as well as the cavitation region for different bearings, no matter which governing equation it is applied with. Especially, when used with the NS equation, the gaseous cavitation model has distinct advantages in accuracy and robustness compared with the commonly used Half-Sommerfeld model and the Rayleigh-Plesset model. Thus it is concluded that this model provides a universal and efficient approach for modeling cavitation in both 2D Reynolds and 3D NS equations, and it will help to prompt the future application of NS equation in more complex bearing problems.