Confined fluid compressibility predicted using molecular dynamics simulation

Fluid compressibility is investigated using molecular dynamics simulation of three fluids with distinct molecular shapes confined to various film thicknesses and subject to a wide range of loads. The effects of film thickness and fluid structure are evaluated, and the simulated densities are compared to predictions of an empirical, bulk fluid compressibility model. Results show that thin films are less compressible than their bulk counterparts and that this difference is related to the effect of confinement on molecular ordering. Additionally, it is found that molecular dynamics simulation can predict bulk compressibility if the model film thickness is sufficiently large.