LIF Study of Plane Jet Bounded in Shallow Water Layer
Publication: Journal of Hydraulic Engineering
Volume 125, Issue 8
Abstract
Rivers, estuaries, and coastal waters represent shallow water layers because the water depths are normally much smaller than the horizontal scales. Pollutant and waste heat disposal often takes the form of a plane jet discharging into such shallow water layers, which is denoted herein as a shallow jet. To predict their mixing characteristics is important for environmental protection. In this experimental study, the field distributions of instantaneous concentration have been measured with a laser-induced fluorescence (LIF) system developed as an attractive and convenient technique for the measurement of concentration fields of both gases and liquids. The instantaneous concentration field illustrates the overall meandering of the plane jet and the role of large-scale turbulent structures in the mixing process. Field distributions of mean concentration and RMS of concentration fluctuation have been obtained by averaging hundreds of digital image frames. The following major results can be concluded from the analysis of these images: (1) All concentration properties of the shallow jet are in scale with the water depth h rather than the slot width B, as is typical for the unbounded planar jet (this result is in agreement with the earlier results of Giger et al. on the velocity field); (2) the concentration half-width grows linearly but faster than for the unbounded case; and (3) the turbulent properties show a lack of self-preservation with increasing distance, a high degree of fluctuation greatly exceeding that of the unbounded case, and a spectral behavior indicative of two-dimensional turbulence.
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References
1.
Abramovich, G. N. (1963). The theory of turbulent jets. MIT Press, Cambridge, Mass.
2.
Arcoumanis, C., McGuirk, J. J., and Palma, J. M. L. M. (1990). “On the use of fluorescent dyes for concentration measurements in water flows.” Experiments in Fluids, 10, 177–180.
3.
Bashir, J., and Uberoi, M. S. (1975). “Experiments on turbulent structure and heat transfer in a two-dimensional jet.” Phys. of Fluids, 18, 405–410.
4.
Batchelor, G. K. (1969). “Computation of energy spectra in homogeneous two-dimensional turbulence.” Phys. of Fluids, 12, 233–238.
5.
Chen, D., and Jirka, G. H. (1998). “Instability characteristics of mixing layer and jet under the joint effects of bottom friction and viscosity.”J. Hydr. Res., Delft, The Netherlands, 36, 815–830.
6.
Chen, D., and Jirka, G. H. (1997). “Absolute and convective instabilities of plane turbulent wakes in shallow-water layer.” J. Fluid Mech., Cambridge, U.K., 338, 157–172.
7.
Chen, D., and Jirka, G. H. (1995). “Experimental study of plane turbulent wakes in a shallow water layer.” Fluid Dyn. Res., 16, 11–41.
8.
Chen, D., and Jirka, G. H. (1993). “Mixing characters and meandering mechanism of a plane jet bounded in a shallow water layer.” Proc., Hydr. Engrg. '93, ASCE, New York, H. W. Shen, S. T. Su, and F. Wen, eds., Vol. 2, 2147–2152.
9.
Chen, D., and Jirka, G. H. ( 1991). “Pollutant mixing in wake flows behind islands in shallow water.” Environmental hydraulics, J. H. W. Lee and Y. K. Cheung, eds., Balkema, Rotterdam, The Netherlands, 371–378.
10.
Crow, S. C., and Champagne, F. H. (1971). “Order structure in jet turbulence.” J. Fluid Mech., Cambridge, U.K., 48, 547–591.
11.
Davies, A. E., Keffer, J. F., and Baines, W. D. (1975). “Spread of a heated plane turbulent jet.” Phys. of Fluids, 18, 770–775.
12.
Dracos, T., Giger, M., and Jirka, G. H. (1992). “Plane turbulent jets in a bounded fluid layer.” J. Fluid Mech., Cambridge, U.K., 241, 587–614.
13.
Fischer, H. B., List, E. J., Imberger, J., and Brooks, N. H. (1979). Mixing in inland and coastal waters. Academic, San Diego.
14.
Giger, M., Dracos, T., and Jirka, G. H. (1991). “Entrainment and mixing in plane turbulent jets in shallow water.”J. Hydr. Res., Delft, The Netherlands, 29(5), 615–641.
15.
Koochesfahani, M. M., and Dimotakis, P. E. (1985). “Laser-induced fluorescence measurements of mixing fluid concentration in a liquid plane shear layer.” AIAA J., 23(11), 1700–1707.
16.
Kotsovinos, N. E., and List, E. J. (1977a). “Plane turbulent buoyant jets: I: Integral properties,” J. Fluid Mech., Cambridge, U.K., 81, 25–44.
17.
Kotsovinos, N. E. (1977b). “Plane turbulent buoyant jets: II: Turbulence structure.” J. Fluid Mech., Cambridge, U.K., 81, 45–62.
18.
Kychakoff, G., Howe, R. D., Hanson, R. K., and McDaniel, J. C. (1982). “Quantitative visualization of combustion species in a plane.” Appl. Optics, 21(18), 3225–3227.
19.
Kychakoff, G., Howe, R. D., and Hanson, R. K. (1984). “Visualization of turbulent flame fronts with planar laser–induced fluorescence.” Sci., 224(4647), 382–384.
20.
List, E. J. (1982). “Turbulent jets and plumes.” Ann. Rev. Fluid Mech., 14, 189–212.
21.
Nash, J., Jirka, G. H., and Chen, D. (1995). “Large scale planar laser induced fluorescence in turbulent density stratified flows.” Experiments in Fluids, 19, 297–304.
22.
Papantoniou, P. N., and List, E. J. (1988). “Investigation of round vertical turbulent buoyant jets.” J. Fluid Mech., Cambridge, U.K., 195, 341–391.
23.
Paranthoen, P., Fouari, A., Dupont, A., and Lecordier, J. C. (1988). “The dispersion measurements in turbulent flows (boundary-layer and plane jet).” Int. J. Heat and Mass Transfer, 31, 153–165.
24.
Tennekes, H., and Lumley, J. L. (1989). A first course in turbulence. MIT Press, Cambridge, Mass.
25.
Tong, C. N., and Warhaft, Z. (1995). “The passive scalar dispersion and mixing in a turbulent jet.” J. Fluid Mech., Cambridge, U.K., 292, 1–38.
Information & Authors
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Published In
Journal of Hydraulic Engineering
Volume 125 • Issue 8 • August 1999
Pages: 817 - 826
History
Received: Mar 24, 1997
Published online: Aug 1, 1999
Published in print: Aug 1999
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