SynopsisWe report results of Brownian dynamics simulations of the steady state and transient rheological behavior of bead and spring chain models in elongational flow. The simulations include examination of the effects of excluded volume, hydrodynamic interactions, chain length, and maximum bond extension. Hydrodynamic interactions are modeled by the Rotne-Prager-Yamakawa tensor. The steady state results for the rheological properties of finitely extensible nonlinear elastic (FENE) chains in the absence of hydrodynamic interactions and excluded volume interactions are compared with the analytic FENE-PM theory of Wedgewood and co-workers. For bead and spring models with short bond lengths, excluded volume and hydrodynamic interactions are shown to affect the steady state rheological properties significantly. 0 1995 Society of Rheology.

We report preliminary rcsuhs of simulations of the steady-state rheological behavior Ibr scmidilutc polymer solutions of bead-and-spring chain models in phmar Coucttc flow. The simulations include examination of tile effects of excluded volume, hydrodynamic interactions, and density. Hydrodynamic interactio,as are modeled by the Rotne-Prager Yanlakawa tensor. Tile simulations arc based on the nonequilibrium Brownian dynamics algorithm of Erlnak and McCammon. In addition to the spring potential between neighboring beads in the chain, the interaction between any two beads in the solution is modeled using a shifted, repulsive Lenuard Jones potential. Lees Edward sliding brick boundary conditions arc used Ibr consistency with tile Couette flow field.