Theses and Dissertations

Zhiyong Duan

Issuing Body

Mississippi State University

Advisor

Martin, L. James

Committee Member

Bridges, H. David

Committee Member

Truax, D. Dennis

Committee Member

Stockstill, L. Richard

Committee Member

McAnally, H. William

Date of Degree

5-5-2007

Document Type

Dissertation - Open Access

Major

Civil Engineering

Degree Name

Doctor of Philosophy

College

James Worth Bagley College of Engineering

Department

Department of Civil and Environmental Engineering

Abstract

The transfer of sparingly soluble gases across the air-water interface has significant effects on the distribution of the constituents in aquatic ecosystems. Gas-liquid transfer rate determines the flux of the sparingly soluble gases driven by the concentration difference. Considerable stream-driven gas-liquid transfer rate formulae have been developed. They have reasonable predictions in one-dimensional uniform flows. However, their applications in more complex cases such as three-dimensional flows are problematic. Furthermore, the wind effects are not incorporated into these formulae. New models need to be developed for gas-liquid transfer rate in three-dimensional flows that incorporate the effects of both wind and streamflow. In this study, first, a model of gas-liquid transfer rate in non-isotropic turbulent flows is developed. Second, a general stream-driven gas-liquid transfer rate model is developed for the normal ranges of water depth and flow velocity in natural rivers. Third, a wind-stream-driven gas-liquid transfer rate model is developed. Fourth, a model of surface renewal rate caused by turbulence from transition location of shear flows is developed. Fifth, a gas-liquid transfer rate model for wind and dynamic three-dimensional flow systems is developed. A computer program is coded and applied to various cases from simple one-dimensional uniform flow systems to complex wind and dynamic three-dimensional flow systems. A specific model can be selected from the series models for a specific application based on the application requirements and the acceptable computation complexity.

URI

https://hdl.handle.net/11668/15229

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