title: Simulation of two- and three-dimensional dense-fluid shear flows via nonequilibrium molecular dynamics: comparison of time-and-space-averaged stresses from homogeneous Doll's and Sllod shear algorithms with those from boundary-driven shear.
abstract: Homogeneous shear flows (with constant strainrate dv(x)/dy) are generated with the Doll's and Sllod algorithms and compared to corresponding inhomogeneous boundary-driven flows. We use one-, two-, and three-dimensional smooth-particle weight functions for computing instantaneous spatial averages. The nonlinear normal-stress differences are small, but significant, in both two and three space dimensions. In homogeneous systems the sign and magnitude of the shearplane stress difference, Pxx-Pyy, depend on both the thermostat type and the chosen shearflow algorithm. The Doll's and Sllod algorithms predict opposite signs for this normal-stress difference, with the Sllod approach definitely wrong, but somewhat closer to the (boundary-driven) truth. Neither of the homogeneous shear algorithms predicts the correct ordering of the kinetic temperatures: Txx > Tzz > Tyy.
authors.affiliation: Ruby Valley Research Institute, Highway Contract 60, Box 598, Ruby Valley, Nevada 89833, USA.
authors.forename: Wm G
authors.initials: WG
authors.lastname: Hoover
authors.forename: Carol G
authors.initials: CG
authors.lastname: Hoover
authors.forename: Janka
authors.initials: J
authors.lastname: Petravic