Login (DCU Staff Only)
Login (DCU Staff Only)

DORAS | DCU Research Repository

Explore open access research and scholarly works from DCU

Advanced Search

On the assessment of numerical interface capturing methods for two fluid flow applications

Albadawi, Abdulaleem (2014) On the assessment of numerical interface capturing methods for two fluid flow applications. PhD thesis, Dublin City University.

Abstract
Two-fluid flows play an important role in many industrial applications. One attractive property is their ability to induce significant increases in mass and/or heat transfer. Bouncing and sliding bubbles are one of the two-fluid flow mechanisms which are known to give rise to very high heat transfer coefficients in heat exchangers. The present study of the full process of bubble growth, rise, impact, and bounce presents particular challenges because of the interaction between the three phases (gas, liquid, and solid) and in particular at the triple contact line. The present work attempts to answer the following question: "To what extent can the available numerical interface capturing methods and contact line boundary conditions capture the correct behaviour of bubble dynamics under several two-fluid flow processes (bubble growth, detachment, rise, and bounce)?" Three diffierent numerical methods (Volume of Fluid (VOF), Level Set (LS), and coupled CLSVOF) are considered. The wetting dynamics of the bubble against solid surfaces are modelled using both static and dynamic contact angles. The numerical simulations are performed using both commercial and open source softwares (ANSYS-Fluent®-v13, OpenFOAM® , and TransAT©). A simple coupled VOF with LS method (S-CLSVOF) for improved surface tension implementation is also proposed and tested by comparison against the standard VOF solver in OpenFOAM. The numerical results are assessed by comparison against experimental data obtained by a research team at the Fluid and Heat Transfer Research Group in Trinity College Dublin (Ireland) as a part of a collaborative project funded by the Science Foundation of Ireland. The assessment of the numerical results highlights the strong sensitivity of the bubble dynamics predicted numerically on the implemented surface tension model, the interface capturing method, and the Capillary number. The analysis of the bubble dynamics during the bouncing process demonstrates the importance of refining the mesh at solid surfaces in order to capture accurately the bubble behaviour during the collision process
Metadata
Item Type:Thesis (PhD)
Date of Award:November 2014
Refereed:No
Supervisor(s):Delauré, Yan
Uncontrolled Keywords:Multiphase flow; Volume of fluid; Level set; Bubble flow
Subjects:Engineering > Computational fluid dynamics
Mathematics > Numerical analysis
DCU Faculties and Centres:Research Initiatives and Centres > Scientific Computing and Complex Systems Modelling (Sci-Sym)
DCU Faculties and Schools > Faculty of Engineering and Computing > School of Mechanical and Manufacturing Engineering
Use License:This item is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 3.0 License. View License
Funders:Science Foundation Ireland
ID Code:20019
Deposited On:21 Nov 2014 13:38 by Yan Delaure . Last Modified 24 Jan 2023 13:53
Documents

Full text available as:

[thumbnail of PhDAAlbadawi.pdf]
Preview
PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
9MB
Downloads

Downloads

Downloads per month over past year

Archive Staff Only: edit this record