Elasto-Hydrodynamic Bearing Model in Powertrain Multi-Body Simulation

Multi-body simulation is a well-established simulation technique in the analysis of internal combustion engines dynamics. The enhancement of multi-body simulation especially regarding flexible structures included effects of structural dynamics in the analysis and helped not only to broaden the field of application but also improved quality of the results. In connection to that there is a steady increase in the need for enhanced and refined modeling approaches for technical subsystems such as journal bearings. The article on hand will present the elasto-hydrodynamic journal bearing module for the software FEV Virtual Engine which is a vertical application to the generic multi-body simulation suite Adams. The scope will focus on the two main aspects of an elasto-hydrodynamic journal bearing model which are the numerical evaluation of the hydrodynamic lubrication in the journal bearing and the interaction between the lubricant film and the structural dynamics of the surrounding environment. The hydrodynamic lubrication task is treated on the basis of the Reynolds equation which is discretized via the finite element method and solved in accordance with mass-conservation in the lubrication gap. The coupling of the fluid and structural dynamics makes use of the flexible body approach in the software FEV Virtual Engine and provides a complete interaction between the journal bearing hydrodynamics and the full range of structure dynamics. The integrity of the presented approach is verified by the comparison with published reference data. The hydrodynamic solution is approved by a comparison with CFD-based results which solved the full set of Navier-Stokes equations. While the elasto-hydrodynamic coupling is approved by an analysis of a high-loaded journal bearing for different structural designs.