Dilution and Penetration of Vertical Negatively Buoyant Thermal Jets
Publication: Journal of Hydraulic Engineering
Volume 138, Issue 10
Abstract
Five series of experiments were performed to study the penetration and dilution properties of vertical negatively buoyant thermal jets (thermal fountains). The flow was turbulent, and the densimetric Froude number based on the radius of the discharge varied from 4.7 to 24. The experiments were conducted in the laboratory by discharging hot water vertically downward into a colder-water environment that had a temperature greater than 15°C. Under these conditions, the water equation of state was practically linear, and the downward negatively buoyant thermal jet was dynamically similar to an upwards negatively buoyant dense jet of equal densimetric Froude number. The temperature fields associated with the negatively buoyant jets were measured with arrays of fast responding thermocouples and were used to study the jet penetration and dilution properties. Detailed analyses of the temperature data revealed large fluctuations of jet penetration in the vertical direction. The mean and maximum vertical jet penetrations obtained in this study using temperature data were consistent with the results of previous studies based on visual data. In contrast, smaller fluctuations of jet penetration occurred in the horizontal direction, and the maximum horizontal penetration of the return flow, at the level of the source (), was . This value is about one-half of the mean vertical jet penetration. On the other hand, the minimum dilution of the returning fluid at the source height just outside of the nozzle was .
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Acknowledgments
The financial support provided by the Natural Sciences and Engineering Research Council of Canada (NSERC) is gratefully acknowledged.
References
Abraham, G. (1967). “Jets with negative buoyancy in homogeneous fluid.” J. Hydraul. Res., 5(4), 235–248.
Baddour, R. E. (1991). “Thermal hydraulic jump: Theory and experiment.” J. Field Mech., 226, 243–256.
Baddour, R. E. (1994). “Thermal saline bubble plumes.” Recent research advances in the fluid mechanics of turbulent jets and plumes, Davis, P. A., and Valente Neves, M. J., eds., NATO ASI Series E, 225, 117–129.
Baddour, R. E., and Zhang, H. (2009). “Density effect on round turbulent hypersaline fountains.” J. Hydraul. Eng., 135(1), 57–59.
Baines, W. D., Turner, J. S., and Campbell, I. H. (1990). “Turbulent fountains in an open chamber.” J. Fluid Mech., 212, 557–592.
Bloomfield, L. J., and Kerr, R. C. (2000). “A theoretical model of a turbulent fountain.” J. Fluid Mech., 424, 197–216.
Chu, V. H. (1975). “Turbulent dense plumes in laminar cross flow.” J. Hydraul. Res., 13(3), 263–279.
Gungor, E., and Roberts, P. J. W. (2009). “Experimental studies on vertical dense jets in a flowing current.” J. Hydraul. Eng., 135(11), 935–948.
James, W. P., Vergara, I., and Kim, K. (1983). “Dilution of a dense vertical jet.” J. Environ. Eng., 109(6), 1273–1283.
Kaye, N. B., and Hunt, G. R. (2006). “Weak fountains.” J. Fluid Mech., 558, 319–328.
Kikkert, G. A., Davidson, M. J., and Nokes, R. I. (2007). “Inclined negatively buoyant discharges.” J. Hydraul. Eng., 133(5), 545–554.
Marti, C. L., Antenucci, J. P., Luketina, D., Okely, P., and Imberger, J. (2011). “Near-field dilution characteristics of a negatively buoyant hypersaline jets generated by a desalination plant.” J. Hydraul. Eng., 137(1), 57–65.
McDougall, T. J. (1981). “Negative buoyant vertical jets.” Tellus, 33(3), 313–320.
McLellan, T. N., and Randall, R. E. (1986). “Measurement of brine jet height and dilution.” J. Waterw. Port Coast. Ocean Eng., 112(2), 200–217.
Nemlioglu, S., and Roberts, P. J. W. (2006). “Experiments on dense jets using 3D Laser-Induced Fluorescence.” Proc., 4th Int. Conf. on Marine Waste Water Disposal and Marine Environment, DVD, Marine Waste Water Disposal (MWWD) Organization, Turkey.
Papakonstantis, I. L., Christodoulou, G. C., and Papanicolaou, P. N. (2011). “Inclined negatively buoyant jets 2: Concentration measurements.” J. Hydraul. Res., 13–22.
Pincince, A. B., and List, E. J. (1973). “Disposal of brine into an estuary.” J. Water Pollut. Control Fed., 45(11), 2335–2344.
Roberts, J. W., Ferrier, A., and Daviero, G. (1997). “Mixing in inclined dense jets.” J. Hydraul. Eng., 123(8), 693–699.
Roberts, P. J. W., and Toms, G. (1987). “Inclined dense jets in flowing currents.” J. Hydraul. Eng., 113(3), 323–341.
Shao, D., and Law, A. (2010). “Mixing and boundary interaction of 30° and 45° inclined dense jets.” Environ. Fluid Mech., 10, 521–533.
Tong, S. S., and Stolzenbach, K. D. (1979). “Submerged discharges of dense effluents.”, Ralph M. Parsons Laboratory, Massachusetts Institute of Technology, Cambridge, MA.
Turner, J. S. (1966). “Jets and plumes with negative or reversing buoyancy.” J. Fluid Mech., 26(4), 779–792.
Zeitoun, M. A., Mcllhenny, W. F., and Reid, R. O. (1970). “Conceptual designs of outfall systems for desalting plants.”, Office of Saline Water, U.S. Dept. of Interior, Washington, DC.
Zhang, H., and Baddour, R. E. (1998). “Maximum penetration of vertical round dense jets at small and large Froude numbers.” J. Hydraul. Eng., 124(5), 550–553.
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Published In
Journal of Hydraulic Engineering
Volume 138 • Issue 10 • October 2012
Pages: 850 - 857
Copyright
© 2012 American Society of Civil Engineers.
History
Received: Aug 24, 2011
Accepted: Feb 29, 2012
Published online: Mar 3, 2012
Published in print: Oct 1, 2012
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