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Buoyant slot jets into stagnant or flowing environments

Cederwall, Klas (1971) Buoyant slot jets into stagnant or flowing environments. W. M. Keck Laboratory of Hydraulics and Water Resources Report, 25. California Institute of Technology , Pasadena, CA. (Unpublished)

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The diffusion following the release of a buoyant slot jet into a confined, uniformly flowing environment has been studied. A dimensionless analysis reveals the complexity of the problem; there are in general four governing dimensionless numbers. However, if the overall mixing and not the details of the process of diffusion is of importance, we can define basic flow regimes using a reduced number of parameters. Experiments were conducted first with a horizontal, buoyant slot jet into stagnant, ambient fluid. Observed trajectories and centerline dilutions were in good agreement with existing theories. In addition, two sets of experiments were perform ed with a vertical and a horizontal buoyant slot jet issuing into a uniformly flowing stream. A two-layer flow analysis provided the rationale for a classification of flow regimes. It was found that the mechanism of upstream intrusion of jet effluent is characterized primarily by a gross densimetric Froude number based on the ambient flow velocity and the buoyancy flux from the source. However, the formation of an upstream wedge may be hampered due to the effect of initial flux of momentum in the downstream direction. When the buoyant slot jet cannot entrain all the oncoming flow, while maintaining the typical jet or plume behavior, then the jet flow pattern breaks up and there is efficient mixing close to the source.

Item Type:Report or Paper (Technical Report)
Additional Information:© 1971 W. M. Keck Laboratory of Hydraulics and Water Resources. California Institute of Technology. I would like to express my deep gratitude to Dr. Norman H. Brooks for many valuable discussions on the subject of this study. For construction of the laboratory equipment, I am much indebted to Mr. Elton F. Daly, Supervisor of the Laboratory, and his assistants, Mr. Carl A. Green and Mr. Robert L. Greenway. A warm thank you is extended to Mrs. Arvilla F. Krugh for typing this manuscript. The writer has had a stipend paid by the Swedish Board for Technical Developlllent (STU) during a temporary research appointment at the W. M. Keck Laboratory of Hydraulics and Water Resources, California Institute of Technology. The work has been supported by Research Grant No. 16070 DGY of the Water Quality Office, Environmental Protection Agency, entitled Dispersion in Hydrologic and Coastal Environments.
Group:W. M. Keck Laboratory of Hydraulics and Water Resources
Funding AgencyGrant Number
Environmental Protection Agency (EPA)16070 DGY
Series Name:W. M. Keck Laboratory of Hydraulics and Water Resources Report
Issue or Number:25
Record Number:CaltechKHR:KH-R-25
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Usage Policy:You are granted permission for individual, educational, research and non-commercial reproduction, distribution, display and performance of this work in any format.
ID Code:25995
Deposited By: Imported from CaltechKHR
Deposited On:20 Nov 2008
Last Modified:03 Oct 2019 03:10

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