Instantaneous Discharge of Buoyant Fluid in Cross-Flow
Publication: Journal of Hydraulic Engineering
Volume 124, Issue 11
Abstract
Artificial instantaneous discharge of buoyant fluid in ambient waters is usually carried out at the time of maximum cross-flow so that the resulting dilution is optimal. The determination of the characteristics of this problem is important for environmental impact study but has seldom been studied. To investigate the transport, mixing, and dilution of an isolated cloud of buoyant fluid in cross-flow ambient, a three-dimensional buoyancy extended k-ε model is employed. The computed results show that two flow regimes exist. First is the initial dumping regime in which the effect of crosscurrent and the associated turbulence on the longitudinal width and the average dilution is insignificant as compared to the effect of buoyancy on those quantities. The flow and mixing characteristics in this regime are close to those in the case of stagnant ambient. Second is the ultimate regime in which the effect of buoyancy on the longitudinal width and the average dilution is small as compared to the effect of cross-flow on those quantities. In the ultimate regime, the crosscurrent produces ambient turbulence that increases the longitudinal width of the cloud (and hence increases the dilution), but only slightly affects the vertical frontal position of the cloud. Laboratory experiments are also conducted for the verification of the model and both results are in reasonable agreement.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Abraham, G. (1971). “The flow of round buoyant jets issuing vertically into ambient fluid flowing in a horizontal direction.”Publ. No. 81, Delft Hydr. Lab., Delft, The Netherlands.
2.
Businger, J. A., Wyngaard, J. C., Izumi, Y., and Bradley, E. F.(1971). “Flux-profile relationships in the atmospheric surface layer.”J. Atm. Sci., 28, 181–189.
3.
Chen, C. J., and Nikitopoulos, C. P.(1979). “On the near field characteristics of axisymmetric turbulent buoyant jets in a uniform environment.”Int. J. Heat Mass Transfer, 22, 245–255.
4.
Chu, V. H., and Lee, J. H. W.(1996). “General integral formulation of turbulent buoyant jets in cross-flow.”J. Hydr. Engrg., ASCE, 122(1), 27–34.
5.
Fan, L. N. (1967). “Turbulent buoyant jets into stratified or flowing ambient fluids.”Rep. No. KH-R-15, California Inst. of Technol., Pasadena, Calif.
6.
Jirka, G. H., and Fong, H. L. M.(1981). “Vortex dynamics and bifurcation of buoyant jets in crossflow.”J. Engrg. Mech. Div., ASCE, 107(3), 479–499.
7.
Koh, R. C. Y., and Chang, Y. C. (1973). “Mathematical model for barged ocean disposal of wastes.” Pacific Northwest Envir. Res. Lab. Nat. Envir. Res. Ctr., Corvallis, Ore.
8.
Lee, J. H. W., and Cheung, V.(1990). “Generalized Lagrangian model for buoyant jets in current.”J. Envir. Engrg., ASCE, 116(6), 1085–1106.
9.
Lee, J. H. W., Rodi, W., and Wong, C. F.(1996). “Turbulent line momentum puffs.”J. Engrg. Mech., ASCE, 122(1), 19–29.
10.
Li, C. W.(1990). “Advection simulation by minimax-characteristics methods.”J. Hydr. Engrg., ASCE, 116(9), 1138–1144.
11.
Li, C. W.(1997). “Convection of particle thermals.”J. Hydr. Res., Delft, The Netherlands, 35(3), 363–376.
12.
Li, C. W., and Yu, T. S.(1996). “Numerical investigation of turbulent shallow recirculating flows by a quasi-three-dimensional k-ε model.”Int. J. Numer. Methods in Fluids, 23, 485–501.
13.
Li, C. W., and Zhang, F.(1996). “Three-dimensional simulation of thermals using a split-operator scheme.”Int. J. Numer. for Heat and Fluid Flow, 6(2), 25–36.
14.
Morton, B. R., Nguyen, K. C., and Cresswell, R. W. (1994). “Similarity and self-similarity in the motion of thermals and puffs.”Recent research advances in the fluid mechanics of turbulent jets and plumes, Kluwer Academic Publishers, Boston, Mass., 89–116.
15.
Nezu, I., and Nakagawa, H. (1993). “Turbulence in open-channel flows.” Int. Assn. for Hydr. Res., Kyoto Univ., Kyoto, Japan.
16.
Patankar, S. V., Basu, D. K., and Alpay, S. A.(1977). “Prediction of the three-dimensional velocity field of a deflected turbulent jet.”J. Fluids Engrg., Trans., ASME, 99, 758–762.
17.
Rodi, W. (1979). “Turbulence models and their application in hydraulics.” Univ. of Karlsruhe, Karlsruhe, Germany.
18.
Scorer, R. S.(1957). “Experiments on convection of isolated masses of buoyant fluid.”J. Fluid Mech., Cambridge, England, 2, 583–594.
19.
Sin, Y. S., and Zhang, L. W. (1994). “Numerical modelling of sludge dumping in a stratified environment.”Proc., Int. Conf. on Hydr. in Civ. Engrg., 327–332.
20.
Sullivan, P. J.(1972). “The penetration of a density interface by heavy vortex rings.”Water, Air Soil Pollution, Dordrecht, The Netherlands, 1, 322–336.
21.
Turner, J. S.(1964). “The dynamics of spheroidal masses of buoyant fluid.”J. Fluid Mech., Cambridge, England, 19, 481–490.
22.
Viollet, P. L. (1990). “On the modelling of low speed variable density and reacting flows with complex geometries.”Proc., 4th Int. Symp. on Refined Flow Modelling and Turbulence Measurements, 7–16.
23.
Woodward, B. (1959). “The motion in and around isolated thermals.”Quarterly J. Royal Meteorological Soc., Bracknell, England, 85, 144– 151.
24.
Yanenko, N. N. (1971). The method of fractional steps. Springer-Verlag New York, Inc., New York.
25.
Younus, and Chaudhry(1994). “A depth-averaged k-ε turbulence model for the computation of free-surface flow.”J. Hydr. Res., Delft, The Netherlands, 32(3), 415–444.
26.
Yu, T. S., and Li, C. W.(1994). “Efficient higher-order backward characteristics schemes for transient advection.”Int. J. Numer. Methods in Fluids, 19, 997–1012.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 124 • Issue 11 • November 1998
Pages: 1161 - 1176
Copyright
Copyright © 1998 American Society of Civil Engineers.
History
Published online: Nov 1, 1998
Published in print: Nov 1998
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.