Masters Theses

Keywords and Phrases

Adaptive Grid Refinement; Computational Fluid Dynamics; Microfluidics; Numerical Modeling; Wicking Fabric

Abstract

"The use of microfluidics to transfer fluids without applying any exterior energy source is a promising technology in different fields of science and engineering due to their compactness, simplicity and cost-effective design. In geotechnical engineering, to increase the soil's strength, hydrophilic wicking fibers as type of microfluidics have been employed to transport and drain water out of soil spontaneously by taking advantage of natural capillary force without using any pumps or other auxiliary devices. The objective of this study is to understand the scientific mechanisms of the capability for wicking fiber to drain both gravity and capillary water out of soil fills.

In this work, wicking fibers were numerically modeled as open microchannels. The effect of the geometry and wettability on the spontaneous flow were analyzed. A 3D computational fluid dynamics-based model was developed to predict the transient movement of the meniscus in microchannels of different geometries. The Volume-of-Fluid (VOF) method was employed along with an in-house developed algorithm to refine the grid only at the air-water interface to reduce the computational effort. Analytical and numerical criteria were derived to determine the critical contact angle for spontaneous flow in different geometry open microchannels. It was found that the aspect ratio and channel geometry have a significant effect on the water filling velocity and mass flowrate. The study was extended to water drainage from unsaturated soils and the minimum negative inlet pressure which represents the maximum soil suction was determined numerically for spontaneous flow for different microchannel geometry. Results of this study can provide an implication in the design of wicking fibers and other microfluidic systems"--Abstract, page iv.

Advisor(s)

Deng, Wen

Committee Member(s)

Smith, Joseph D.
Wang, Jianmin
Zhang, Xiong

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

M.S. in Environmental Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2018

Journal article titles appearing in thesis/dissertation

  • Numerical modeling of capillary-driven flow in open microchannels

Pagination

xiii, 73 pages

Note about bibliography

Includes bibliographic references.

Rights

© 2018 Mehrad Gholizadeh Ansari, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 11376

Electronic OCLC #

1051222956

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