Current tools and techniques for EHL modelling

We describe the construction of genuine black box software to model in detail elastohydrodynamically lubricated contacts. Such models are necessarily built on a basis of sophisticated numerical software, since the operating parameters encountered in engine and machine components (e.g. an automotive valve train) span a very wide range of conditions from the nearly steady and hydrodynamic case to extreme EHD conditions with rapid transients. As transient phenomena are responsible for the non-failure of many machine components under EHD conditions, we regard the ability to model them as critical. The traditional correlations for lubricant oil film thickness (survey functions) do not account for transients. We are therefore using EHD modelling software as the core of several engine component simulation programs.