title: Schmidt number effects in dissipative particle dynamics simulation of polymers.
abstract: Simulation studies for dilute polymeric systems are presented using the dissipative particle dynamics method. By employing two different thermostats, the velocity-Verlet and Lowe's scheme, we show that the Schmidt number (S(c)) of the solvent strongly affects nonequilibrium polymeric quantities. The fractional extension of wormlike chains subjected to steady shear is obtained as a function of S(c). Poiseuille flow in microchannels for fixed polymer concentration and varying number of repeated units within a chain is simulated. The nonuniform concentration profiles and their dependence on S(c) are computed. We show the effect of the bounce-forward wall boundary condition on the depletion layer thickness. A power law fit of the velocity profile in stratified Poiseuille flow in a microchannel yields wall viscosities different from bulk values derived from uniform, steady plane Couette flow. The form of the velocity profiles indicates that the slip flow model is not useful for the conditions of these calculations.
authors.affiliation: Division of Applied Mathematics, Brown University, Providence, Rhode Island 02912, USA. sjoh0341@dam.brown.edu
authors.forename: Vasileios
authors.initials: V
authors.lastname: Symeonidis
authors.forename: George Em
authors.initials: GE
authors.lastname: Karniadakis
authors.forename: Bruce
authors.initials: B
authors.lastname: Caswell