Computational Modelling of Mesophase Pitches' Shear Rheology

摘要

Flow modelling of mesophase pitches is performed using a previously formulated mesoscopic viscoelastic rheological theory that takes into account flow-induced texture transformations. A complete extra stress tensor equation is developed from first principles for liquid crystal materials under non-homogeneous arbitrary flow. Predictions for a given simple shear flow, under non-homogeneous conditions, for the apparent shear viscosity and first normal stress differences are presented. The rheological functions are explained using macroscopic orientation effects, which predominate at low shear rates. The predicted normal stress differences and apparent shear viscosity are in agreement with experimental measurements.