Pore-scale simulation of immiscible multiphase flow with moving contact lines using level sets
Abstract/Contents
- Abstract
- Accurate Modeling of immiscible two-phase flow at the pore-scale requires the development of high-fidelity numerical methods that allow for high-resolution representation of fluid interfaces, while honoring the conservation laws of momentum, mass, and energy. The multiphase numerical methods must capture the interfacial jump conditions and model the multiscale physics of contact-line dynamics. The objective of this work is to model accurately the surface-tension force and the moving contact line (MCL) boundary condition using the level-set framework coupled with the Navier-Stokes equations. To model the MCL, we implemented the Cox-Voinov slip-based model that describes the viscous bending occurring of the fluid interface near the contact line. The Cox-Voinov model determines the contact angle boundary condition. Several test cases have shown that the Cox-Voinov model leads to excellent agreement with the experimental results without the need to explicitly resolve the nanoscale slip-length. We developed a new multiscale level-set method that efficiently captures the evolution of thin films covering the solid surface. In this multiscale framework, the MCL singularity is removed using a film model that takes into account the intermolecular surfaces forces in the vicinity of the contact line. The new multiscale method matches Bretherton's scaling law in a drainage process, where the deposited film thickness on the solid wall depends on the balance between the viscous and capillary forces. The new multiscale level-set method can simulate two-phase flow with a capillary number as low as $10^{-6}$. Also, the proposed multiscale approach provides a framework to study the influence of intermolecular forces and surface roughness on the interfacial dynamics. The framework is demonstrated for droplet-based microfluidics problems and the effect of water salinity on the pore-scale dynamics. We also implemented the contact angle on complex solid surfaces. The results for moving interfaces inside complex confined geometries are accurate and can simulate flows of capillary numbers on the order of $10^{-5}$. The Haines jump is accurately modeled in a smoothly constricted channel. Finally, we present a new conservative surface tension (CST) model in the level-set framework. We show for the first time that the surface-tension model is both conservative and well-balanced. We demonstrate that the CST model simulates the Marangoni stresses accurately and models complex topological deformations such as interface breakup.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2017 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Abu-Al-Saud, Motaz O |
|---|---|
| Associated with | Stanford University, Department of Energy Resources Engineering. |
| Primary advisor | Tchelepi, Hamdi |
| Thesis advisor | Tchelepi, Hamdi |
| Thesis advisor | Aziz, Khalid, Ph. D |
| Thesis advisor | Kovscek, Anthony R. (Anthony Robert) |
| Advisor | Aziz, Khalid, Ph. D |
| Advisor | Kovscek, Anthony R. (Anthony Robert) |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Motaz O. Abu-Al-Saud. |
|---|---|
| Note | Submitted to the Department of Energy Resources Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2017. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2017 by Motaz Omar Abu AlSaud
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