Numerical simulations of wormlike micelles flows in micro-fluidic T-shaped junctions

Numerical simulations of non-Newtonian fluids such as wormlike micellar solutions in confined geometries are of great interest in the oil industry. Their main property called shear-banding is a brutal transition from a very viscous state to a very fluid state above a certain threshold value of shear stress. This feature leads to a very complex behavior in 3D flows. A modified version of the Johnson-Segalman's model, adapted to our situation (flows with a strong extensional component) is presented. A particular attention is paid to inlet and outlet boundary conditions, and a Poiseuille-like submodel is derived in order to get natural velocity and stress profiles that can be used at the boundaries. A numerical method is then developed, and stability issues are presented. Our results show the interest of the modified Johnson Segalman's model performed in this article. A set of 3D numerical simulations are then presented in order to understand the influence of the junction geometry upon the jamming effects observed with this kind of fluids. (C) 2014 IMACS. Published by Elsevier B.V.All rights reserved.