Simulation of radial journal bearings using the FSI approach and a multi-phase model with integrated cavitation

Journal bearings are an essential component in mechanical engineering. While the fundamental functional principle is well known, the internal processes in a bearing and the complex interactions between lubrication film and bearing structure have hitherto not been fully researched. Traditionally journal bearing analysis is carried out by special simulation codes based on lubrication theory or use of the Reynolds equation. To take phenomena such as turbulence, cavitation or heat transfer into account, empirical and numerical models are integrated into the calculations. These codes have proven to be efficient and sufficiently accurate for fundamental bearing analysis but are also subject to certain limitations in that they do not allow visualisation of physical phenomena such as cavitation, recirculation or elastohydrodynamic effects in complex geometries. This paper presents an approach based on state of the art numerical fluid structure interaction (FSI) methods. Application of three dimensional computational fluid dynamics (CFD) and finite element methods (FEM) allows the analysis of arbitrary bearing geometries. Furthermore, this approach also permits a detailed analysis of flow phenomena inside the bearing.