Relaxation of dilute polymer solutions following extensional flow

摘要: Abstract The relaxation of dilute polymer solutions following stretch in uniaxial extensional flow is investigated via Brownian dynamic simulations a flexible freely-draining bead-rod chain. chain are compared to FENE dumbbell and numerical calculations FENE-PM A universal curve for the stress decay from steady-state found by shifting results lie on described an initially straight For all models investigated, initial rapid decreases at rate which scales large Weissenberg number, Wi as 2 . Our good qualitative some cases quantitative agreement with available experimental data: it particularly predicting after largest strains. We find hysteresis comparing versus birefringence during startup subsequent dumbbell, but not latter model lost preaveraging nonlinear terms. also displays configuration hysteresis. observed these recent experiments involving polystyrene-based Boger fluids.