Hydrodynamics of chiral nematics in a channel and sudden contraction geometry

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Morawo, Isreal, Grecov, Dana
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908518779453440
author Morawo, Isreal
Grecov, Dana
author_facet Morawo, Isreal
Grecov, Dana
contents This study investigates the influence of chirality, viscous effects, and confinement geometry on the flow dynamics and defect structures of cholesteric liquid crystals (CLCs) using numerical simulations. As chiral strength increases, $π$-twist defects form at low chirality and progressively organize into hexagonal domains resembling blue phase--like (BP-like) structures at higher chirality. At sufficiently high chirality and aspect ratios, skyrmion-like configurations emerge, indicating the formation of dynamic analogs of equilibrium phases under flow. Sudden contraction geometries reveal how aspect ratio and elastic interactions promote flow disturbances and defect development. Analyses of velocity and scalar order parameter ($S$) distributions demonstrate strong coupling between molecular alignment and hydrodynamic fields, with localized vortices forming around $τ^-$ defects in regions of low $S$ and velocity. Temporal evaluations of velocity fluctuations uncover chaotic flow regimes at low Ericksen numbers, characterized by irregular defect motion and skewed probability density functions. These findings offer new insights into CLC structure formation and flow behavior, with potential applications in defect engineering, microfluidics, soft robotics, and photonic materials.
format Preprint
id arxiv_https___arxiv_org_abs_2506_11933
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Hydrodynamics of chiral nematics in a channel and sudden contraction geometry
Morawo, Isreal
Grecov, Dana
Soft Condensed Matter
Mathematical Physics
This study investigates the influence of chirality, viscous effects, and confinement geometry on the flow dynamics and defect structures of cholesteric liquid crystals (CLCs) using numerical simulations. As chiral strength increases, $π$-twist defects form at low chirality and progressively organize into hexagonal domains resembling blue phase--like (BP-like) structures at higher chirality. At sufficiently high chirality and aspect ratios, skyrmion-like configurations emerge, indicating the formation of dynamic analogs of equilibrium phases under flow. Sudden contraction geometries reveal how aspect ratio and elastic interactions promote flow disturbances and defect development. Analyses of velocity and scalar order parameter ($S$) distributions demonstrate strong coupling between molecular alignment and hydrodynamic fields, with localized vortices forming around $τ^-$ defects in regions of low $S$ and velocity. Temporal evaluations of velocity fluctuations uncover chaotic flow regimes at low Ericksen numbers, characterized by irregular defect motion and skewed probability density functions. These findings offer new insights into CLC structure formation and flow behavior, with potential applications in defect engineering, microfluidics, soft robotics, and photonic materials.
title Hydrodynamics of chiral nematics in a channel and sudden contraction geometry
topic Soft Condensed Matter
Mathematical Physics
url https://arxiv.org/abs/2506.11933