Please use this identifier to cite or link to this item:
https://hdl.handle.net/10356/5274
Title: | Numerical modeling of multiphase flows in microchannels | Authors: | Yap, Yit Fatt | Keywords: | DRNTU::Engineering::Mechanical engineering::Fluid mechanics | Issue Date: | 2007 | Source: | Yap, Y. F. (2007). Numerical modeling of multiphase flows in microchannels. Doctoral thesis, Nanyang Technological University, Singapore. | Abstract: | The present work devises and implements numerical procedures to simulate multiphase flows where precise prediction of these interfaces is essential. A three-phase flow model with two fluids and a solid phase involving two moving interfaces, i.e. fluid-fluid (F-F) and fluid-solid (F-S) interfaces, is proposed. Two limiting cases of the model are two-fluid flow and fluid-solid flow. The F-F interface is captured using a level-set method. Two mass conservation schemes, i.e. Global (GMC) and Local (LMC) Mass Correction Schemes, are presented to ensure mass conservation. While GMC is for general two-fluid flow problems, LMC is developed for stratified two-fluid flows. Artificial viscosity is introduced in selected region away from the F-F interface during the advection of the level-set function and shown to improve numerical stability. A new fixed-grid F-S interface tracking technique is proposed. Solids, represented by local distance functions, are tracked explicitly. The procedure can handle flows with multiple complex shaped solids. The F-F interface tracking procedure is extended to the case where there is a slip velocity at the solid surfaces as encountered in the modeling of electrophoresis of particles. A set of combined conservation equations is employed for the physical domain consists of the three phases. Surface tension effects at the F-F interface, both curvature and Marangoni driven, are incorporated using the Continuum Surface Force model. Solution of the governing equations together with the F-F interface capturing and F-S interface tracking procedures are implemented in a finite volume method. Validation of the present model is made against available results in two-fluid and fluid-solid flows. The applications of the present model in a large variety of multiphase flow problems are demonstrated. | URI: | https://hdl.handle.net/10356/5274 | DOI: | 10.32657/10356/5274 | Rights: | Nanyang Technological University | Fulltext Permission: | open | Fulltext Availability: | With Fulltext |
Appears in Collections: | MAE Theses |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
MAE-THESES_1026.pdf | 2.04 MB | Adobe PDF | ![]() View/Open |
Page view(s) 10
396
Updated on Feb 25, 2021
Download(s) 10
231
Updated on Feb 25, 2021
Google ScholarTM
Check
Altmetric
Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.