Residual film thickness following immiscible fluid displacement in noncircular microchannels at large capillary number

Dynamics of immiscible-fluid displacement in a capillary tube.

Thickness of residual wetting film in liquid-liquid displacement.

Core-annular flow is common in nature, representing, for example, how streams of oil, surrounded by water, move in petroleum reservoirs. Oil, typically a nonwetting fluid, tends to occupy the middle (core) part of a channel, while water forms a surrounding wall-wetting film. What is the thickness of the wetting film? A classic theory has been in existence for nearly 50 years offering a solution...

Mixing process of immiscible fluids in microchannels

The paper is concerned with experimental investigations and numerical simulations of immiscible flows in microchannels in the presence of interfacial surface tension. The aim of the present study is to model the unsteady dynamics of the vortical structures and interface shape in the Y-branching geometries with square cross-sections. The tested fluids are Newtonian and weakly elastic polyacrylam...

Finite - Difference Large - Displacement Gas - Film

To numerically solve squeezed gas-lm forces in a narrow air-gap between moving surfaces, an electrical-equivalent circuit mesh is formed that realizes the nonlinear, modiied Reynolds equation at discrete surface positions. The model is usable when investigating gas-lm forces for large gap displacements and pressure variations. It is also usable as a reference when simple, compact models for squ...

Laminar Flow in Microchannels With Noncircular Cross Section

Analytical solutions are presented for laminar fully developed flow in micro-/ minichannels of hyperelliptical and regular polygonal cross sections in the form of compact relationships. The considered geometries cover a wide range of common simply connected shapes including circle, ellipse, rectangle, rectangle-with-round-corners, rhombus, star-shape, equilateral triangle, square, pentagon, and...