Computer Simulation of Shear-Induced Phase Separation and Rheology in Two-Component Viscoelastic Fluid

Abstract

We numerically study the dynamics of polymer solutions in two dimensions at a temperature above the equilibrium coexistence curve under shear flow. Our model is based on the Lagrangian picture of fluid dynamics. We can incorporate viscoelastic effects into the model by introducing a kind of fluid particles which have memories of their own past history. We carry out computer simulations and observe that shear-induced phase separation occur and the system shows a shear thinning rheological property. The most remarkable result is that the dependence of normal stress coefficient on shear rate changes at a shear rate which is comparable to inverse of the stress relaxation time. Our results imply that the shear-induced phase separation can change qualitative features of rheological response.