Simulations of lubricants in confined geometries

We examine the shear Row of hexadecane and squalane confined between plates with nm separation using molecular dynamics simulations. For both molecules substantial slip occurs at the walls and the density profile exhibits strong oscillations. In contrast to surface force apparatus measurements, our calculated effective viscosities are not much greater than bulk viscosities, but the simulations shear rates are much larger than the experimental ones. The actual viscosity calculated using the shear rate measured from the observed velocity profile is almost equal to the bulk viscosity within uncertainty.