Ocean Outfalls. II: Spatial Evolution of Submerged Wastefield
Publication: Journal of Hydraulic Engineering
Volume 115, Issue 1
Abstract
Some of the basic features of submerged wastefield formation in stratified currents are reported in this paper. Dilution increased with distance from the diffuser in the initial mixing region until it attained a maximum value, which is the initial dilution, after which it remained constant. By assuming a model of buoyancy‐induced turbulence collapse, expressions for the observed dependency on current speed in the forced entrainment regime of initial dilution, rise height, and mixing region length were obtained. An expression for lateral spreading in parallel currents was derived which was found to be of the same form as for unstratified currents, except that the rate of spreading in stratified currents is much slower. An expression for the rate of spreading in perpendicular currents was derived by applying results from mixed‐region collapse. An applications example shows that the initial mixing region can extend for several hundred meters downstream from the discharge. Because of gravitational spreading, a line diffuser will produce a wastefield width comparable to the diffuser length for most oceanic conditions, suggesting that Y or similarly complex diffuser configurations are not necessary to produce a widely dispersed wastefield.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Amen, R., and Maxworthy, T. (1980). “The gravitational collapse of a mixed region into a linearly stratified fluid.” J. Fluid Mech., 96, 65–80.
2.
Buhler, J. (1986). Discussion of “Spreading layer of a two‐dimensional buoyant jet.” J. Hydr. Engrg., ASCE, 112(10), 992–994.
3.
Cederwall, K. (1971). “Buoyant slot jets into stagnant or flowing environments.” Rept. No. KH‐R‐25, W. M. Keck Laboratory of Hydraulics and Water Resources, California Inst. of Technology.
4.
Fischer, H. B., et al. (1979). Mixing in Inland and Coastal Waters. Academic Press.
5.
Hopfinger, E. J. (1985). “Turbulence collapse in stratified fluids.” Proc. IUTAM Symp. on Mixing in Stratified Fluids, Margaret River, Australia, 25–29 August.
6.
Kao, T. W. (1976). “Principal stage of wake collapse in a stratified fluid: two‐dimensional theory.” Phys. Fluids, 19(8), 1071–1074.
7.
Koh, R. C. Y. (1983). “Wastewater field thickness and initial dilution.” J. Hydr. Engrg., ASCE, 109(9), 1232–1240.
8.
Larsen, J., and Sorensen, T. (1968). “Buoyancy spread of wastewater in coastal regions.” Eleventh Conference on Coastal Engineering, London, England, 2, 1397–1402.
9.
Lin, J. T., and Pao, Y. H. (1979). “Wakes in stratified fluids.” Ann. Rev. Fluid Mech., 11, 317–338.
10.
Manins, P. C. (1976). “Intrusion into a stratified fluid.” J. Fluid Mech., 74, part 3, 547–560.
11.
Maxworthy, T. (1980). “On the formation of nonlinear internal waves from the gravitational collapse of mixed regions in two and three dimensions.” J. Fluid Mech., 96, Part 1, 47–64.
12.
Roberts, P. J. W. (1979a). “Line plume and ocean outfall dispersion.” J. Hydr. Div., ASCE, 105(4), 313–331.
13.
Roberts, P. J. W. (1979b). “A mathematical model of initial dilution for deepwater ocean outfalls.” Proc. of Specialty Conf. on Conservation and Utilization of Water and Energy Resources, San Francisco, Aug. 8–11, 218–225.
14.
Roberts, P. J. W. (1979c). “Two‐Dimensional Flow Field of Multiport Diffuser,” J. Hydr. Div., ASCE, 105(5), 605–611.
15.
Roberts, P. J. W., and Matthews, P. R. (1987). “Behavior of low buoyancy jets in a linearly stratified fluid.” J. of Hydr. Res., 25(4), 503–519.
16.
Roberts, P. J. W., Snyder, W. H., and Baumgartner, D. J. (1989). “Ocean outfalls. I: submerged wastefield formation.” J. Hydr. Engrg., ASCE, 115(1), 1–25.
17.
Rouse, H. (1947). “Gravitational diffusion from a boundary source in two‐dimensional flow.” J. of Applied Mechanics, American Society of Mechanical Engineers, A225‐A228.
18.
Scorer, R. S. (1959). “The behavior of chimney plumes.” Int. J. Air Poll., 1, 198–220.
19.
Thorpe, S. A. (1982). “On the layers produced by rapidly oscillating a vertical grid in a uniformly stratified fluid.” J. Fluid Mech., 124, 391–409.
20.
Wright, S. J. (1977). “Effects of ambient crossflows and density stratification on the characteristic behavior of round turbulent buoyant jets.” Rept. No. KH‐R‐36. W. M. Keck Laboratory of Hydraulics and Water Resources, California Institute of Technology.
21.
Wright, S. J. (1984). “Buoyant jets in density‐stratified crossflow.” J. Hydr. Engrg., ASCE, 110(5), 643–656.
22.
Wu, J. (1969). “Mixed region collapse with internal wave generation in a density‐stratified medium.” J. Fluid Mech., 35, part 3, 531–544.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 115 • Issue 1 • January 1989
Pages: 26 - 48
Copyright
Copyright © 1989 ASCE.
History
Published online: Jan 1, 1989
Published in print: Jan 1989
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.