Record Details
Field | Value |
---|---|
Title | Diffusion in a variable density liquid under conditions of turbulent, steady flow |
Names |
Harris, Dennis Roy
(creator) Behlke, Charles (advisor) |
Date Issued | 1964-04-30 (iso8601) |
Note | Graduation date: 1964 |
Abstract | The diffusion process in a variable density, turbulent flow is a factor which greatly influences the waste disposal characteristics of tidal estuaries. Waste disposal from cities and industries, is posing an increasing threat to the estuarine environment. Accurate prediction of the effects of proposed waste outfalls in well-mixed estuaries (which predominate during the most critical waste disposal season) is very desirable. The most used analytical tool for the prediction of waste concentrations in well-mixed estuaries, is the one-dimensional conservation of mass equation. A lack of knowledge concerning the diffusion process and a resulting inability to predict the coefficient of turbulent diffusion, is a major limitation to the use of this tool. Closed form solutions to the equation of mass conservation are not sufficiently accurate for most real estuaries because of the required simplifying assumptions. Field determination of the average diffusion coefficients has allowed numerical solutions for average steady-state concentrations. For the purpose of providing a tool for predicting the cyclical variation of waste concentrations and improving our understanding of the diffusion process, a dimensional analysis for the instantaneous diffusion coefficient (considering only bottom shear and longitudinal density gradients) was made. Experimental work was designed to determine the relationships between dimensionless parameters obtained by the systematic method of Buckingham. The narrow range of flows and depths for which consistent results could be obtained did not allow a complete determination of the relationships. However, the nature of the relationships obtained, indicated that they could serve as the correspondence between model and prototype for determining the longitudinal density gradient effects on the diffusion coefficient in well-mixed estuaries. Further studies are required to verify these relationships over a wider range of flows and depths. |
Genre | Thesis/Dissertation |
Topic | Sewage disposal |
Identifier | http://hdl.handle.net/1957/48588 |