Molecular dynamics characterization of thin film viscosity for EHL simulation
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Molecular simulations were used to characterize changes in lubricant viscosity that may occur during thin film elastohydrodynamic lubrication (EHL). Molecular dynamics simulations were performed at variable wall speed and film thickness such that the effects of both parameters could be evaluated. Using this approach it was found that the viscosity of thin films under large shear is subject to both shear thinning and oscillation with film thickness. A composite model was developed that incorporated both effects. The expected impact that this model might have on an EHL interface was evaluated using a continuum simulation. An overall decrease in viscosity with some oscillation near the interface edges was predicted due to the molecularly modeled thin film effects.
Keywordsnanotribology EHL with non-Newtonian lubricants viscosity
The authors would like to express their sincere gratitude for the support of the US National Science Foundation IGERT Program, Office of Naval Research, and Department of Energy. This research was also supported in part by the National Science Foundation through TeraGrid resources provided by NCSA.
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