عنوان مقاله [English]
In recent years, with growing population and industrialization of the world, desalination techniques have developed drastically to supply the rising needs of coastal cities to fresh water. The brine is the second product of the producing fresh water process in the desalination facilities, that is usually discharged into the sea through marine outfalls (surface and submerged). The main purpose of the outfall is to enhance the dilution and reduce the impact on the local environment. In this study, in order to investigate the impact of the shape of the surface discharge channel, rectangular and trapezoidal sections with the equivalent diameter were used to discharge wastewater with negative buoyancy into stagnant and non-stratified water bodies. Experiments have been carried out in a dark room and processed using digital analysis. The location of plunge point, impact point and the dilution in this point, and the location of the ultimate point and dilution at this point were the flow characteristics studied in this research. According to the shape impact and less hydraulic conflict with the surroundings, trapezoidal section had better geometric characteristics compared to rectangular section. Results of the experiments were presented in the form of non-dimensional diagrams and equations. Finally, statistical indices such as Root Mean Square Error (RMSE) and R-Square (R2) were used to verify the accuracy of the presented dimensionless equations. The results indicated that the closer the shape of surface channel discharge is to the best hydraulic cross section (semicircular), the better geometric and mixing characteristics would be obtained for the flow along near-field area. In this way, prediction of flow characteristics and design of actual samples of these outfalls will be possible.
Abessi, O. & Roberts, W.P., 2015, "Effect of nozzle orientation on dense jets in stagnant environments", Journal of Hydraulic Engineering, 10.1061/(ASCE), HY.1943-7900.0001032, 06015009.
Abessi, O. & Roberts, W.P., 2015, "Dense jet discharges in shallow water", Journal Hydraulic Engineering, ISSN 0733-9429/04015033(13).
Abessi, O., 2011, "Analysis of surface discharge of negatively buoyant effluents into non-stratified water bodies", PhD Thesis, Iran University of Science and Technology, School of Civil Engineering, Tehran, Iran. (In Persian)
Abessi, O., Roberts, W.P., 2014, "Multiport diffusers for dense discharges", Journal Hydraulic Engineering, 140 (8), 04014032-1-04014032-12.
Abessi, O., Saeedi, M., Davidson, M. & Hajizadeh Zaker, N., 2012, "Flow classification of negatively buoyant surface discharges in an ambient current", Journal Coastal Research, DOI 10.2112/JCOASTRES-D-10-00131.1, 28 (1-a), 148-155.
Abessi, O., Saeedi, M., Bleninger, T. & Davidson, M., 2012, "Surface discharge of negatively effluent in unstratified stagnant water", Journal of Hydro-Environment Research, 6, 181-193.
Amon, R.M.W. & Benner, R., 1998, "Seasonal patterns of bacterial abundance and production in the Mississippi River plume and their importance for the fate of enhanced primary production", FEMS Microbiology Ecology, 35 (3), 289-300.
Bleninger, T. & Jirka, G., 2008, "Modelling and environmentally sound management of brine discharges from desalination plants", Journal of Desalination, 221, 585-597.
Chu, V.H. & Jirka, G.H., 1986, "Surface buoyant jets" In: Encyclopedia of fluid mechanics, Chap. 25, Gulf, Houston.
Cipollina, A., Brucato, A., Grisafi, F. & Nicosia, S., 2005, "Bench-scale investigation of inclined dense jets", Journal of Hydraulic Engineering, 131(11), 1017-1022.
Crowe, A.T., Davidson, M.J., & Nokes, R.I., 2012, "Maximum height and return point velocities of desalination brine discharges", 18th Australasian Fluid Mechanics Conference Launceston, Australia.
Fischer, H. B., List, E. J., Koh, C. Y., Imberger, J. & Brooks, N. H., 1979, Mixing in inland and coastal waters, Academic Press, Inc., Orlando, Florida.
Gholamreza-Kashi, S., Martinuzzi, R.J. & Baddour, R.E., 2007, "Mean flow field of a nonbuoyant rectangular surface jet", Journal of Hydraulic Engineering, 133 (2), 234-239.
Jirka, G.H., 2007a, "Buoyant surface discharges into water bodies. II: jet integral model", Journal of Hydraulic Engineering, 133 (9), 1021-1036.
Jirka, G.H., Adams, E.E. & Stolzenbach, K.D., 1981, "Buoyant surface jets", Journal of Hydraulics Division., 107, (11), 1467-1487.
Jones, G., Nash, D., Doneker, L. & Jirka, G.H., 2007, "Buoyant surface discharge into water bodies I: Flow classification and prediction methodology", Journal of Hydraulic Engineering, ASCE, Vol. 133, No. 9, 1010-1020.
Jones, G.R., Nash, J.D. & Jirka, G.H., 1996, "CORMIX3: An expert system for mixing zone analysis and prediction of buoyant surface discharge", DeFrees Hydraulics Laboratory, Cornell University.
Kikkert, G., A., 2006, "Buoyant jets with tow and three-dimensional trajectories", PhD Thesis, University of Canterbury, Christchurch, New Zealand.
Kassem, J.A.M. & Khan, J.A., 2003, "Three-dimensional modeling of negatively buoyant flow in diverting channels", Journal Hydraulic Engineering, 129 (12), 936-947.
Kikkert , G., Davidson, J. & Nokes, I., 2007, "Inclined negatively buoyant discharges", Journal of Hydraulic Engineering, 133, 545-554.
Law Adrian, W.K., Fun Ho, W. & Monismith, S.G., 2004, "Double diffusive effect on desalination discharges", Journal of Hydraulic Engineering, 130 (5), 450-457.
Lia, C.C.K. & Lee, J.H.W., 2012, "Mixing of inclined dense jets in stationary ambient", Journal of Hydro-Environment Research, 6, 9-28.
MacCallum, R. C., Browne, M. W. & Sugawara, H. M., 1996, "Power analysis and determination of sample size for covariance structure modelling", Psychological Methods, 1, 130-149.
Marti, C. L., Antenucci, J. P., Luketina, D., Okely, P. & Imberger, J., 2011, "Near-field dilution characteristics of a negatively buoyant hypersaline jet generated by a desalination plant", Journal Hydraulic of Engineering, 137(1), 57-65.
Miller, R.S., Madnia, C.K. & Givi, P., 1995, "Numerical simulation of non-circular jets", Journal Computers and Fluids, 24, (1), 1-25.
Nash, J.D. & Jirka, G.H., 1996, "Buoyant surface discharges into unsteady ambient flows", Journal of Dynamics Atmospheres and Oceans, 24 (1-4), 75-84.
Nokes, R., 2008, Image Stream Version 7.00, User’s Guide, Department of Civil and Natural Resources Engineering University of Canterbury, Christchurch, New Zealand.
Oliver, C.J., Davidson, M.J. & Nokes, R.I., 2013, "Removing the boundary influence on negatively Pincince, A.B., List, E.J., 1973. Disposal of brine into an estuary", Journal of Water Pollut. Control Fed., 45, 2335-2344.
Roberts, P.J.W., Ferrier, A. & Daviero, G., 1997, "Mixing in inclined dense jets", Journal of Hydraulic Engineering, 123 (8), 693-699.
Saeedi, M., Farahani, A. Abessi, O. & Bleninger, T., 2012, "Laboratory studies defining flow regimes for negatively buoyant surface discharges into crossflow", Journal of Environmental Fluid Mechanics, 12, 439-449, DOI 10.1007/s10652-012-9245-4.
Shao, D., Law, A.W.K., 2010, "Mixing and boundary interactions of 30 and 45 inclined dense jets", Journal of Environmental Fluid Mechanics, 10 (5), 521-553.
Silva, W.P. & Silva, C.M.D.P.S., 1999-2011, "LAB Fit curve fitting software (nonlinear regression and treatment of data program)", V 7.2.48, Online, available at the World Wide Web at: www.labfit.net
Tarrade, L., Miller, B. & Smith, G., 2010, "Physical modelling of brine dispersion of desalination plant outfalls", 6th International Conference on Marine Wastewater Discharges, MWWD 2010, Langkawi, Malaysia, 25 - 29.
USEPA, 1980a, Ambient water quality criteria, EPA 440/5-80-015 to 079, U.S. Environmental Protection Agency, Washington, D.C.
Xiao, J., Travis, J.R. & Breitung, W., 2009, "Non-boussinesq integral model for horizontal turbulent buoyant round jets", ScienceandTechnology of Nuclear Installations", doi:10.1155/2009/862934.