Theoretical study on Poiseuille flow of thixotropic yield stress fluids: an exact solution.

The steady pipe flow of thixotropic yield stress fluids has been investigated theoretically based on a modified isotropic kinematic hardening (mIKH) model. Analytical solution is derived for a specific case (m = n = 1) and a general semi-analytical solution is put forward as well. The effect of thixotropic yield stress on shear rate and velocity profiles is illustrated by comparing to other well-known solutions. Moreover, the influences of model parameters are examined. It is worth noting that shear banding may occur at the yielded surface in case of a sufficiently large Bingham number, thixotropic number, and flow index, but a sufficient small value of structure-related exponent. [ABSTRACT FROM AUTHOR]