- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Theses and Dissertations /
- Random walk model applicable to rivers
Open Collections
UBC Theses and Dissertations
UBC Theses and Dissertations
Random walk model applicable to rivers Vine, Jason
Abstract
The disposal of waste effluent from industrial and municipal sources into rivers for the purpose of dilution is a common practice. Dilution occurs in the near-field due to specifics of the diffuser design, and in the mid-field due to parameters of the ambient environment. The ability to predict downstream dilution is of interest to regulatory officials and engineers who wish to design such disposal systems. A random walk model has been developed which is geared towards use in rivers. The model only performs mid-field calculations, however the potential exists to accept the results from a near-field model as input. The model attempts to account for the major velocity structures that occur in an open channel, including transverse and vertical shear, secondary currents due to flow through a bend, and turbulent fluctuations. Equations describing such phenomena are obtained from the literature. Laboratory experiments are conducted to verify the validity of some of these equations. As expected from theory, the research confirms that random walk modelling predicts the same results as Fickian diffusion. Arguments are presented as to the choice of a suitable timestep for use with a random walk model. Several key parameters of the random walk are identified, and their effect on the stability and accuracy of the model results are examined. The model is applied to the disposal of effluent from a pulp and paper mill located in Prince George, B.C. Results agree acceptably with a popular diffusion model as well as with digital imagery of the plume. Plots of plume width and dilution are produced for various river flow rates which may be expected at Prince George.
Item Metadata
| Title |
Random walk model applicable to rivers
|
| Creator | |
| Publisher |
University of British Columbia
|
| Date Issued |
1996
|
| Description |
The disposal of waste effluent from industrial and municipal sources into rivers
for the purpose of dilution is a common practice. Dilution occurs in the near-field due to
specifics of the diffuser design, and in the mid-field due to parameters of the ambient
environment. The ability to predict downstream dilution is of interest to regulatory
officials and engineers who wish to design such disposal systems.
A random walk model has been developed which is geared towards use in rivers.
The model only performs mid-field calculations, however the potential exists to accept
the results from a near-field model as input. The model attempts to account for the major
velocity structures that occur in an open channel, including transverse and vertical shear,
secondary currents due to flow through a bend, and turbulent fluctuations. Equations
describing such phenomena are obtained from the literature. Laboratory experiments are
conducted to verify the validity of some of these equations. As expected from theory, the
research confirms that random walk modelling predicts the same results as Fickian
diffusion. Arguments are presented as to the choice of a suitable timestep for use with a
random walk model. Several key parameters of the random walk are identified, and their
effect on the stability and accuracy of the model results are examined.
The model is applied to the disposal of effluent from a pulp and paper mill located
in Prince George, B.C. Results agree acceptably with a popular diffusion model as well
as with digital imagery of the plume. Plots of plume width and dilution are produced for
various river flow rates which may be expected at Prince George.
|
| Extent |
4676124 bytes
|
| Genre | |
| Type | |
| File Format |
application/pdf
|
| Language |
eng
|
| Date Available |
2009-03-14
|
| Provider |
Vancouver : University of British Columbia Library
|
| Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
|
| DOI |
10.14288/1.0050372
|
| URI | |
| Degree | |
| Program | |
| Affiliation | |
| Degree Grantor |
University of British Columbia
|
| Graduation Date |
1996-11
|
| Campus | |
| Scholarly Level |
Graduate
|
| Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.