Correlation lengths in hydrodynamic models of active nematics. Issue 38 (2nd September 2016)

• Record Type: Journal Article
• Authors: Hemingway, Ewan J.; Mishra, Prashant; Marchetti, M. Cristina; Fielding, Suzanne M.
• Is Part Of: Soft matter. Volume 12:Issue 38(2016)
• Page Start: 7943
• Page End: 7952
• Publication Date: 2016-09-02
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/c6sm00812g
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : We study the turbulent dynamics of active nematics using 2D simulations and identify the single active length scale that characterizes structure in the fluid. Abstract : We examine the scaling with activity of the emergent length scales that control the nonequilibrium dynamics of an active nematic liquid crystal, using two popular hydrodynamic models that have been employed in previous studies. In both models we find that the chaotic spatio-temporal dynamics in the regime of fully developed active turbulence is controlled by a single active scale determined by the balance of active and elastic stresses, regardless of whether the active stress is extensile or contractile in nature. The observed scaling of the kinetic energy and enstrophy with activity is consistent with our single-length scale argument and simple dimensional analysis. Our results provide a unified understanding of apparent discrepancies in the previous literature and demonstrate that the essential physics is robust to the choice of model.