Energy and pressure of shearing fluids at different state points.
Nonequilibrium molecular dynamics simulations are reported at different strain rates (gamma) and thermodynamic state points for a shearing atomic fluid interacting via a Lennard-Jones potential. Our simulations are performed at the Lennard-Jones triple point, a point midway between the triple point and the critical point, and a high point closer to the critical temperature. We find that, for the mid-point and high point, the energy and hydrostatic pressures have strain-rate dependencies of gamma(2), in contrast to the gamma(3/2) dependencies predicted by mode coupling theory. This analytical dependence is consistent with a Taylor series expansion of these quantities as powers of the strain rate tensor. Only at the triple point does the pressure and energy display a nonanalytical dependence on gamma(3/2).
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Centre for Molecular Simulation and School of Information Technology, Swinburne University of Technology, PO Box 218, Hawthorn, Victoria 3122, Australia.
Marcelli
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Todd
B D
BD
Sadus
R J
RJ