Breakup of thin liquid films with viscous interfaces

Thin liquid films are ubiquitous in nature and have many practical applications. From biological films to the curtain coating process, thin films are present in both large and small scales. Despite their importance, understanding the stability of these films remains a significant challenge due to the fluid-fluid interface that is free to deform, affected by interfacial tension and complex rheological behavior. Instabilities in thin films are often caused by van der Waals attractions, which can lead to the rupture of the layer. To investigate the rupture dynamics, numerical methods are commonly used, such as asymptotic derivations of the lubrication theory or interface tracking methods. In this paper, we present a computational study of the breakup dynamics of a stationary thin liquid sheet bounded by a passive gas with a viscous interface, using the arbitrary Lagrangian-Eulerian method and the Boussinesq-Scriven constitutive law to model the rheological behavior. Our results demonstrate that the stability of thin liquid films is influenced by both surface rheology and disjoining effects and that the viscous character of the interface can delay sheet breakup, leading to more stable films.

Automated summary

Thin liquid films are widely encountered in various natural and practical scenarios. Understanding the stability of these films is crucial but challenging due to the complex fluid-fluid interface and interfacial tension. Instabilities in thin films are often caused by van der Waals attractions that lead to rupture. This paper presents a computational study on the breakup dynamics of a stationary thin liquid sheet with a viscous interface, providing insights into the influence of surface rheology and disjoining effects on film stability.