Pressure-driven changes to spontaneous flow in active nematic liquid crystals

Walton, J., McKay, G., Grinfeld, M. and Mottram, N. J. (2020) Pressure-driven changes to spontaneous flow in active nematic liquid crystals. European Physical Journal E, 43(8), 51. (doi: 10.1140/epje/i2020-11973-8) (PMID:32743686)

Abstract

We consider the effects of a pressure gradient on the spontaneous flow of an active nematic liquid crystal in a channel, subject to planar anchoring and no-slip conditions on the boundaries of the channel. We employ a model based on the Ericksen-Leslie theory of nematics, with an additional active stress accounting for the activity of the fluid. By directly solving the flow equation, we consider an asymptotic solution for the director angle equation for large activity parameter values and predict the possible values of the director angle in the bulk of the channel. Through a numerical solution of the full nonlinear equations, we examine the effects of pressure on the branches of stable and unstable equilibria, some of which are disconnected from the no-flow state. In the absence of a pressure gradient, solutions are either symmetric or antisymmetric about the channel midpoint; these symmetries are changed by the pressure gradient. Considering the activity-pressure state space allows us to predict qualitatively the extent of each solution type and to show, for large enough pressure gradients, that a branch of non-trivial director angle solutions exists for all activity values.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Walton, Dr Joshua and Mottram, Professor Nigel
• Authors: Walton, J., McKay, G., Grinfeld, M., and Mottram, N. J.
• College/School: College of Science and Engineering > School of Mathematics and Statistics > Mathematics
• Journal Name: European Physical Journal E
• Publisher: Springer
• ISSN: 1292-8941
• ISSN (Online): 1292-895X
• Published Online: 04 August 2020
• Copyright Holders: Copyright © 2020 The Authors
• First Published: First published in European Physical Journal E 43(8): 51
• Publisher Policy: Reproduced under a Creative Commons License