Title: Experimental and theoretical study of density jumps on smooth and rough beds
Abstract: Lakes & Reservoirs: Science, Policy and Management for Sustainable UseVolume 15, Issue 4 p. 285-306 Experimental and theoretical study of density jumps on smooth and rough beds Nader Barahmand, Corresponding Author Nader Barahmand Corresponding author. Email: [email protected]Search for more papers by this authorAbolfazl Shamsai, Abolfazl Shamsai Department of Civil Engineering, Science and Research Branch, Islamic Azad University (IAU), Tehran, IranSearch for more papers by this author Nader Barahmand, Corresponding Author Nader Barahmand Corresponding author. Email: [email protected]Search for more papers by this authorAbolfazl Shamsai, Abolfazl Shamsai Department of Civil Engineering, Science and Research Branch, Islamic Azad University (IAU), Tehran, IranSearch for more papers by this author First published: 28 November 2010 https://doi.org/10.1111/j.1440-1770.2010.00442.xCitations: 4Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Abstract Hydraulic jumps in density currents are technically referred to density jumps. These jumps significantly influence the dynamic and quality characteristics of the gravity currents. The density jump is studied theoretically and experimentally in this study by considering the bed roughness. Experiments were performed in a rectangular laboratory flume (0.4 m width; 0.9 m depth; 8.3 m length). Four rough beds comprised of closely packed gravel particles glued onto the horizontal part of the bed were examined. For both smooth and rough beds, a simple relationship was obtained for estimating the conjugate depth ratio as a function of the relative roughness and the upstream densimetric Froude number. The conjugate depth ratio was found to decrease with increasing relative roughness. The results also indicated that, if the entrainment ratio is specified, the minimum value of the upstream densimetric Froude number increases with increasing relative bed roughness. An equation for calculating the maximum possible value of the relative roughness was also determined. The spatial development of the density current for smooth beds was analysed in both super-critical and sub-critical flow regimes. Good similarity collapses of velocity and concentration profiles were obtained for the super-critical section just upstream of the jump. The concentration distributions located just downstream of the jump, however, exhibited a large scattering of measured data, especially near the bed. It was found that this scattering decreases with the distance from the end of the jump. The results of the experimental runs also indicated that, at a distance about nine times the post-jump current thickness from the end of the jump, the non-dimensional vertical profile of mean velocity has a shape similar to that at the pre-jump section. A new reliable relationship was also proposed for calculating the local velocity inside both the wall and jet regions. References Alavian V. (1986) Behavior of density currents on an incline. J. Hydraul. Eng. 112(1), 27–42. 10.1061/(ASCE)0733-9429(1986)112:1(27) Web of Science®Google Scholar Altinakar M. S., Graf W. H. & Hopfinger E. J. (1990) Weakly depositing turbidity current on a small slope. J. Hydraul. Res. 28(1), 55–80. 10.1080/00221689009499147 Web of Science®Google Scholar Altinakar M. S., Graf W. H. & Hopfinger E. J. (1996) Flow structure in turbidity currents. J. Hydraul. Res. 34(5), 713–8. 10.1080/00221689609498467 Web of Science®Google Scholar Baddour R. E. & Abbink H. (1983) Turbulent underflow in a short channel of limited depth. J. Hydraul. Eng. 109(5), 722–40. 10.1061/(ASCE)0733-9429(1983)109:5(722) Web of Science®Google Scholar Cantero M. I. & Garcia M. H. (2001) Sediment management in water reservoirs by jet-induced density currents. Proc., Int. Symp. on Env. Hydr., Tempe, Ariz. Google Scholar Carollo F. G. & Ferro V. (2004) Determinazione delle altezze coniugate del risalto libero su fondo liscio e scabro. Riv. Ingeg. Agrar. 35(4), 1–11 (in Italian). Google Scholar Carollo F. G., Ferro V. & Pampalone V. (2007) Hydraulic jumps on rough beds. J. Hydraul. Eng. 133(9), 989–99. 10.1061/(ASCE)0733-9429(2007)133:9(989) Web of Science®Google Scholar Carollo F. G., Ferro V. & Pampalone V. (2009) A new solution of classical hydraulic jump. J. Hydraul. Eng. 135(6), 527–31. 10.1061/(ASCE)HY.1943-7900.0000036 Web of Science®Google Scholar Chikita K. & Okumura Y. (1990) Dynamics of turbidity currents measured in Katsurasawa reservoir, Hokkido, Japan. J. Hydrol. 177, 323–38. 10.1016/0022-1694(90)90099-J Web of Science®Google Scholar Dallimore C. J., Imberger J. & Ishikawa T. (2001) Entrainment and turbulence in a saline underflow in Lake Ogawara. J. Hydraul. Eng. 127(11), 937–48. 10.1061/(ASCE)0733-9429(2001)127:11(937) Web of Science®Google Scholar Ead S. A. & Rajaratnam N. (2002) Hydraulic jumps on corrugated beds. J. Hydraul. Eng. 128(7), 656–63. 10.1061/(ASCE)0733-9429(2002)128:7(656) Web of Science®Google Scholar Ellison T. H. & Turner J. S. (1959) Turbulent entrainment in stratified flows. J. Fluid Mech. 6, 423–48. 10.1017/S0022112059000738 Web of Science®Google Scholar Fan J. & Morris G. L. (1992) Reservoir sedimentation I: delta and density current deposits. J. Hydraul. Eng. 118(3), 354–69. 10.1061/(ASCE)0733-9429(1992)118:3(354) Web of Science®Google Scholar Fathi-Moghadam M., Torabi Poudeh H., Ghomshi M. & Shafaei M. (2008) The density current head velocity in expansion reaches. Lakes Reservoirs: Res. Manage. 13, 63–8. 10.1111/j.1440-1770.2007.00351.x Google Scholar Firoozabadi B., Farhanieh B. & Rad M. (2003) Hydrodynamics of two-dimensional, laminar turbid density currents. J. Hydraul. Res. 41(6), 623–30. 10.1080/00221680309506894 Web of Science®Google Scholar Fozdar F. M., Parker G. & Imberger J. (1985) Matching temperature and conductivity sensor response characteristics. J. Phys. Oceanogr. 15(11), 1557–69. 10.1175/1520-0485(1985)015<1557:MTACSR>2.0.CO;2 Web of Science®Google Scholar Garcia M. H. (1993) Hydraulic jumps in sediment-driven bottom currents. J. Hydraul. Eng. 119(10), 1094–117. 10.1061/(ASCE)0733-9429(1993)119:10(1094) Web of Science®Google Scholar Hartel C., Carlsson F. & Thunblom M. (2000a) Analysis and direct numerical simulation of the flow at a gravity-current head. Part 2: the Lobe-and-Cleft instability. J. Fluid Mech. 418, 213–29. 10.1017/S0022112000001270 Web of Science®Google Scholar Hartel C., Meiburg E. & Necker F. (2000b) Analysis and direct numerical simulation of the flow at a gravity-current head. Part 1: flow topology and front speed for slip and no-slip boundaries. J. Fluid Mech. 418, 189–212. 10.1017/S0022112000001221 Web of Science®Google Scholar Hosseini S. A., Shamsai A. & Ataie-Ashtiani B. (2006) Synchronous measurements of the velocity and concentration in low density turbidity currents using an Acoustic Doppler Velocimeter. Flow Meas. Instrum. 17, 59–68. 10.1016/j.flowmeasinst.2005.05.002 CASWeb of Science®Google Scholar Hug M. (. Ed.). (1975) Mécanique des fluides appliquée. Editions Eyrolles, Paris, F. Google Scholar Klumpp C. C., Jennifer Bountry J. & Blair Greimann B. (2003) Case studies in dam decommissioning at the Bureau of Reclamation. Proc., World Water Resources Congress, Philadelphia, Pennsylvania. Google Scholar Kneller B. C., Bennett S. J. & McCaffrey W. D. (1999) Velocity structure, turbulence and fluid stresses in experimental gravity currents. J. Geophys. Res. 104, 5281–91. 10.1029/1998JC900077 Web of Science®Google Scholar Lee H. Y. & Yu W. S. (1997) Experimental study of reservoir turbidity current. J. Hydraul. Eng. 123(6), 520–8. 10.1061/(ASCE)0733-9429(1997)123:6(520) PubMedWeb of Science®Google Scholar Lhermitte R. & Serafin R. (1984) Pulse-to-pulse coherent Doppler sonar signal processing techniques. J. Atmos. Ocean. Technol. 1(4), 293–308. 10.1175/1520-0426(1984)001<0293:PTPCDS>2.0.CO;2 Google Scholar Liu J. & Tominaga A. (2003) New development of sediment flushing technique. Proc., World Water Resources Congress, Philadelphia, Pennsylvania. Google Scholar Oehy Ch. & Schleiss A. (2001) Numerical modeling of a turbidity current passing over an obstacle—practical application in Lake Grimsel, Switzerland. Proc., Int. Symp. on Env. Hydr. (CD-ROM), Tempe, Ariz. Google Scholar Oehy Ch. & Schleiss A. (2007) Control of turbidity currents in reservoirs by solid and permeable obstacles. J. Hydraul. Eng. 133(6), 637–48. 10.1061/(ASCE)0733-9429(2007)133:6(637) Web of Science®Google Scholar Parker G., Fukushima Y. & Pantin H. M. (1986) Self-accelerating turbidity currents. J. Fluid Mech. 171, 145–81. 10.1017/S0022112086001404 Web of Science®Google Scholar Rajaratnam N. (1965) The hydraulic jump as a wall jet. J. Hydr. Div. 91(5), 107–32. Google Scholar Regev A., Hassid S. & Poreh M. (2004) Density jumps in smoke flow along horizontal ceilings. Fire Safety J. 39, 465–79. 10.1016/j.firesaf.2004.04.002 Web of Science®Google Scholar Regev A., Hassid S. & Poreh M. (2006) Calculation of entrainment in density jumps. J. Environ. Fluid Mech. 6, 407–24. 10.1007/s10652-006-9000-9 Web of Science®Google Scholar Russell H. A. J. & Arnott R. W. C. (2003) Hydraulic-jump and hyperconcentrated-flow deposits of a glacigenic subaqueous fan: Oak Ridges Moraine, southern Ontario, Canada. J. Sediment. Res. 73(6), 887–905. 10.1306/041103730887 Web of Science®Google Scholar Simpson J. E. (1997) Gravity Currents in the Environment and in the Laboratory, 2nd edn. Cambridge University Press, Cambridge, U.K. Google Scholar Turner J. S. (1979) Buoyancy Effects in Fluids. Cambridge University Press, Cambridge, UK. Google Scholar Wilkinson D. L. & Wood I. R. (1971) A rapidly varied flow phenomenon in a two-layer flow. J. Fluid Mech. 47(2), 241–56. 10.1017/S0022112071001034 Web of Science®Google Scholar Xia Q. & Liu J. (2003) Sediment management at Naodehai reservoir. Proc., World Water Resources Congress, Philadelphia, Pennsylvania. Google Scholar Yih C. S. & Guha C. R. (1955) Hydraulic jump in a fluid system of two layers. Tellus 7(3), 358–66. 10.1111/j.2153-3490.1955.tb01172.x Web of Science®Google Scholar Citing Literature Volume15, Issue4December 2010Pages 285-306 ReferencesRelatedInformation
Publication Year: 2010
Publication Date: 2010-11-28
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
Cited By Count: 4
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot