We present molecular-dynamics results for a dense Lennard-Jones fluid near the triple point subjected to the Couette flow. The method is based on the introduction of stochastic boundary conditions to simulate the contact with a moving thermal wall. The method allows the simulation of bulk properties of the system and the study of the local thermodynamical equilibrium. Furthermore, it gives a physical description of momentum and heat transfer near a Couette wall. We found that the shear viscosity depends on shear rate near the triple point (breakdown of Newton's law) while for a point far from the liquid-solid coexistence line there is no appreciable deviation from Newton's law. In the bulk region, where boundary effects are negligible, we found that the local thermodynamical equilibrium holds for all simulated shear rates (up to 1.14± ${10}^{11}$ ${\sec }^{-1\mathrm{}}$). Moreover, we do not find any dependence on the number of particles used in the simulation. Last we compare the results for the shear-dependent shear viscosity with theoretical predictions for nonlinear behavior.

• Received 25 July 1983

DOI:https://doi.org/10.1103/PhysRevA.29.916