A coupled Ericksen/Allen-Cahn model for liquid crystal droplets

We present a model and discretization that couples the Ericksen model of liquid crystals with variable degree of orientation to the Allen-Cahn equations with a mass constraint. The coupled system models liquid crystal droplets with anisotropic surface tension effects due to the liquid crystal molecular alignment. The total energy consists of the Ericksen energy, phase-field (Allen-Cahn) energy, and a weak anchoring energy that couples the liquid crystal to the diffuse interface. We describe our discretization of the total energy along with a method to compute minimizers via a discrete gradient flow algorithm which has a strictly monotone energy decreasing property. Numerical experiments are given in three dimensions that illustrate a wide variety of droplet shapes that result from their interaction with defects. (C) 2018 Elsevier Ltd. All rights reserved.