Near-Field Mixing Downstream of a Multiport Diffuser in a Shallow River
Publication: Journal of Environmental Engineering
Volume 137, Issue 4
Abstract
Near-field mixing downstream of a multiport diffuser in a wide shallow river was studied with a field dye test. Dye concentrations at different depths and lateral locations were measured. The near-field mixing was analyzed in four zones: the free jet zone, the jet surface-impingement zone, the merging zone, and the vertical mixing zone. Analytical models were proposed to derive the three-dimensional concentration field after the jets impinged the water surface. After the impingement, the dye concentration can be predicted well by treating the multiple jets as a simple mathematical summation of individual jets. The vertical mixing zone was dominated by the riverbed friction-induced turbulence, with little effect from the effluent momentum and buoyancy. The results of the field data were also used to validate the applicability of some existing models for multiport diffusers.
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Acknowledgments
The writers would like to thank C. Krath, F. Bhuiyan, M. Spafford, Z. Pan, N. Hall, K. Sharma, J. Cai, and A. Camino for their help with the field work; P. Fedun for his support in the laboratory; T. McKenna for providing the effluent and diffuser information; and B. Liu for helping with the River2D model. We also give our appreciation to Dr. N. Rajaratnam and Dr. F. Bhuiyan for their advice on this paper.
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Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 137 • Issue 4 • April 2011
Pages: 230 - 240
Copyright
© 2011 American Society of Civil Engineers.
History
Received: Dec 23, 2009
Accepted: Nov 8, 2010
Published online: Nov 11, 2010
Published in print: Apr 1, 2011
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