Julia Yeomans OBE FRS

Abstract:

We investigate the behavior of a tethered polymer in Poiseuille flow using a multiscale algorithm. The polymer, treated using molecular dynamics, is coupled to a solvent modeled by the stochastic rotation algorithm, a particle-based Navier-Stokes integrator. The expected series of morphological transitions of the polymer: sphere to distorted sphere to trumpet to stem and flower to rod are recovered, and we discuss how the polymer extension depends on the flow velocity. Backflow effects cause an effective increase in viscosity, which appears to be primarily due to the fluctuations of the free end of the polymer. © 2005 American Institute of Physics.

Abstract:

We investigate the behavior of a tethered polymer in Poiseuille flow using a multiscale algorithm. The polymer, treated using molecular dynamics, is coupled to a solvent modeled by the stochastic rotation algorithm, a particle-based Navier-Stokes integrator. The expected series of morphological transitions of the polymer: sphere to distorted sphere to trumpet to stem and flower to rod are recovered, and we discuss how the polymer extension depends on the flow velocity. Backflow effects cause an effective increase in viscosity, which appears to be primarily due to the fluctuations of the free end of the polymer.

Abstract:

We use a kinetic theory approach to derive the continuum Navier-Stokes and heat conduction equations for stochastic rotation dynamics, a particle based algorithm for simulating a fluid. Hence we obtain expressions for the viscosity and thermal conductivity in two and three dimensions. The predictions are tested numerically and good agreement is found.