Effect of Bend Wettability on Hydrodynamics of Liquid–Liquid Two-phase Flow in Serpentine Mini Geometry

Abstract

In the present study, liquid−liquid flow dynamics are compared in three different geometries experimentally. These are straight glass capillary, serpentine geometry made of glass capillary, and serpentine geometry made of glass capillary with hydrophobic bends. For all cases, glass capillaries have an inner diameter of 2.4 mm and total length of 1.72 m. Four different liquid pairs are used to investigate the effect of continuous phase properties on flow distribution. Slug, slug droplet, and encapsulated slugs are noticed. The effect of the bend contact angle on flow distribution is explored. It is noticed that the presence of bends is responsible for the slug with droplet generation. Also, hydrophobic bends result in phase inversion that produces the encapsulation. On increasing the continuous phase viscosity, the range of existence of encapsulated region increases. However, the area of encapsulated phase decreases. At the same time, the shape of the encapsulated phase changes from cylindrical to spherical. An empirical correlation is proposed for area encapsulated in terms of non-dimensional numbers.

Film Thickness Studies of Viscous Taylor Droplet Flow

“…Film thickness variation depends on various conditions, and Aussillous and Quéré identified two regions, viz., visco-capillary and visco-inertial, to characterize the film thickness . The other aspects of interest in Taylor droplet flow include wettability, mass transfer, pressure drop, curved channel, rectangular cross section etc. − …”