Access Type

Open Access Dissertation

Date of Award

January 2018

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Mechanical Engineering

First Advisor

Naeim Henein

Second Advisor

Hassan Farhat

Abstract

This work aims to provide an efficient Gunstensen LBM based CFD model, capable of solving complex problems related to droplets behavior in shear and parabolic flows.

Thermal conditions determine the outcome of the physical and transport properties of emulsions during their various processing phases. A better understanding of the intricate relationship between thermal, surfactants and hydrodynamics can help in the optimization of these processes during the production of emulsions. To investigate the outcome of coupling thermal, surfactants and hydrodynamics on emulsions behavior, a robust quasi-steady thermal-surfactants numerical scheme is presented and used here. To validate the model, the rheological behavior of oil-in-water system was investigated. The numerical results matched well the experimental results of the similar oil-in-water system under steady-state thermal conditions. Furthermore, it is shown that the proposed numerical model can handle cases with transient thermal conditions while maintaining good accuracy.

The model has been improved to study the combined effects of temperature, and contact angle on the movement of slugs and droplets of oil in water (O/W) system flowing between two parallel plates and in 3D confined flow study. This is found in the enhanced oil recovery technique which includes thermal, contact angle and surfactant effects for breaking up trapped crude oil.

The model static contact angle due to the deposition of the O/W droplet on a flat surface with simulated hydrophilic characteristic at different fluid temperatures, matched very well the proposed theoretical calculation. Furthermore, the model was used to simulate the dynamic behavior of droplets and slugs deposited on the domain's upper and lower surfaces, while subjected to parabolic flow conditions. The model accurately simulated the contact angle hysteresis for the dynamic droplets cases. It was also shown that at elevated temperatures the required power to transport the mixture diminished remarkably. The aim is to improve our understanding of the underlying physics associated with the secondary and tertiary extraction process of trapped crude oil in wells by injecting hot water.

Finally, the model was utilized for the investigation of the flow behavior of O/W emulsions with the goal of delineating the best practices for transporting these emulsions in circular ducts. The effects of temperature, volume fraction, flow pressure gradient, and surfactants concentration are investigated in a Poiseuille flow setup. A dimensionless power number ratio was introduced and successfully used for guiding the selection of the most cost-efficient means for transporting O/W emulsion.

Download

Share

COinS