Abstract
We present a mesoscale kinetic model for multicomponent flows, augmented with a short range forcing term, aimed at describing the combined effect of surface tension and near-contact interactions operating at the fluid interface level. Such a mesoscale approach is shown to (i) accurately capture the complex dynamics of bouncing colliding droplets for different values of the main governing parameters, (ii) predict quantitatively the effective viscosity of dense emulsions in micro-channels and (iii) simulate the formation of the so-called soft flowing crystals in microfluidic focusers.
Highlights
A thorough knowledge of the dynamic interactions between fluid interfaces is paramount to a deeper understanding of a variety of natural processes and engineering applications, such as combustion, microfluidic coating, food processing and many others
We present an lattice Boltzmann (LB)-based approach for multicomponent flows, based on the colour-gradient model (Leclaire et al 2012), augmented with an additional forcing term which is aimed at representing the effects of the near-contact forces operating at the fluid interface level
We show the capability of the extended LB model to accurately reproduce the correct dynamics of head-on and off-axis collisions between two nx × ny × nz
Summary
A thorough knowledge of the dynamic interactions between fluid interfaces is paramount to a deeper understanding of a variety of natural processes and engineering applications, such as combustion, microfluidic coating, food processing and many others. The coalescence and/or repulsion between droplets or bubbles can be traced to the hydrodynamic drag originating from the relative motion of two fluid interfaces in near contact (Barnocky & Davis 1989; Davis, Schonberg & Rallison 1989; Shi, Brenner & Nagel 1994; Mani, Mandre & Brenner 2010; Rubin et al 2017), and to the combined action of nanoscale attractive and/or repulsive forces, such as van der Waals and electrostatic forces, steric interactions, hydration repulsion and depletion attraction (Bergeron 1999; Stubenrauch & Von Klitzing 2003). A wide body of theoretical and experimental work has elucidated the complex nature of the near-contact interactions which develop within intervening liquid films: from the pioneering works of Gibbs and Marangoni on the thermodynamics of liquid. Succi thin films (see Bergeron (1999) for a comprehensive review) to the separate work of Derjaguin and Overbeek (Derjaguin 1940; Verwey, Overbeek & Overbeek 1999) which culminated in the joint DLVO theory (after its founders, Derjaguin, Landau, Verwey and Overbeek)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
