Eur. Phys. J. Plus (2022) 137: 12
https://doi.org/10.1140/epjp/s13360-021-02250-w

Regular Article

Acoustic transition for a micromorphic model of nematic liquid crystals

DIMA, Università, via Dodecaneso 35, 16146, Genova, Italy

^a maurizio.romeo@unige.it

Received: 23 August 2021
Accepted: 2 December 2021
Published online: 13 December 2021

Abstract

A micromorphic approach to the density–orientation coupling in nematic liquid crystals is exploited to discuss the acoustic transition of its orientational structure. The constitutive model is based on the representation of mass density by the microdensity, whose effectiveness and coherence with classical continuum models were discussed in a previous work. The usual micropolar model is here extended to account for a microstretch contribution which is essential to describe the dynamics of compressible materials. The specific investigation pertains a boundary value problem for a nematic layer with homeotropic structure subject to an incident acoustic wave. We deduce a threshold value of the displacement amplitude on a boundary layer. By a numerical evaluation, we compare the threshold wave velocity with experimental data.