COMPUTATIONAL STUDIES OF DYNAMICS OF PRESSURE-DRIVEN DROPS IN MICRO-CHANNELS

Author

Edward S. Kramer, Southern Illinois University CarbondaleFollow

Date of Award

12-1-2010

Degree Name

Master of Science

Department

Mechanical Engineering

First Advisor

Esmaeeli, Asghar

Abstract

In particulate flows, the flow inertia impacts the motion and size distribution of the particles and this in turn, has a strong implication on global behavior of the emulsions such as their rheological properties. As such, the central goal of most of the investigations on dispersed multiphase flow, so far, has been to understand the phase distribution of particles and to correlate the global behavior of the system with this parameter. For pressure-driven particulate flows in a channel, it is known that the velocity gradient in the channel leads to a lateral force whose magnitude and direction depends on the viscosity and density ratios of the fluids and the drop deformation. This lateral (lift) force is the primary reason behind the various observed modes of phase distribution of the particles. Unfortunately, most of the studies conducted so far have been concerned with the solid particles and for flows at low to moderate Reynolds numbers. Little is known about the dynamics of deformable drops at high Reynolds numbers. The goal of this study is to bridge the gap by direct numerical simulations. A front tracking/finite difference technique is used to solve the Navier-Stokes equations in the fluids inside and outside of the drops. Initially, the drops are randomly distributed in the computational domain their evolutions are followed for a sufficiently long time so that the system reaches a quasi-steady state. The statistics about the flow then will be extracted. The flow inertia is increased incrementally by increasing the pressure gradient.