Pj. Daivis et Dj. Evans, COMPARISON OF CONSTANT-PRESSURE AND CONSTANT VOLUME NONEQUILIBRIUM SIMULATIONS OF SHEARED MODEL DECANE, The Journal of chemical physics, 100(1), 1994, pp. 541-547
We present the results of nonequilibrium molecular dynamics simulation
s of a model decane fluid performed at constant pressure and compare t
hem with results previously obtained from simulations performed at con
stant volume. The strain rate dependence of the viscosity at constant
pressure is found to differ from that obtained previously at constant
volume. The shear thickening at high strain rates observed in constant
volume simulations vanishes when the simulations are performed at con
stant pressure. We also investigate the question of how our low strain
rate data for decane can be accurately extrapolated to zero strain ra
te. We find a well defined first Newtonian region in which the viscosi
ty is independent of strain rate to within errors. The value of the vi
scosity that we obtain in this region agrees well with the zero strain
rate viscosity calculated from the Green-Kubo formula at equilibrium.