Experimental Analysis of Relations Between Coherent Turbulent Structures and Formation of Bedforms

• Autorzy: Termini D. , Sammartano V.
• Języki publikacji: EN

Abstrakty

EN

The present paper describes an experimental investigation on the interactions between flow turbulence and sediment motion. During the experiments, detailed measurements of flow velocity components were carried out using an Acoustic Doppler Velocimeter (ADV). The occurrence of turbulent events (inward interaction, ejection, sweep and burst) was verified through conditioned quadrant analysis. The quantitative information on the spatial and temporal evolution of turbulent events was obtained through space-time correlations of the conditioned data. As the primary objective was to analyse how turbulent structures influence formation of bedforms, the spatial scale of turbulent event evolution has been compared with the wavelength of bed-forms (alternate bars) observed on the bed. The analysis has essentially highlighted that such spatial scale compares well with the wavelength of the bars.

Słowa kluczowe

EN

open channel flow; sediment transport; bed forms; flow turbulence structure

• Wydawca: Institute of Hydro-Engineering of Polish Academy of Sciences
• Czasopismo: Archives of Hydro-Engineering and Environmental Mechanics
• Rocznik: 2008
• Tom: Vol. 55, nr 3-4
• Strony: 125--143
• Opis fizyczny: Bibliogr. 25 poz., il.

Twórcy

autor

Termini D.

autor

Sammartano V.

• Dipartimento di Idraulica ed Applicazioni Ambientali, Facoltá di Ingegneria, Universitá di Palermo, Italy,

Bibliografia

• 1. Berkooz G., Holmez P. and Lumley J. L. (1993) The proper orthogonal decomposition in the analysis of turbulent flows, Ann. Rev. Fluid Mech., 25, 539–575.
• 2. Cantwell B. J. (1981) Organized Motion in Turbulent Flow, Ann. Review Fluid Mechanics, 457–515.
• 3. Corino E. R. and Brodkey R. S. (1969) A visual investigation of the wall region in turbulent flow, Journal of Fluid Mechanics, 37, 1–30.
• 4. Cellino M. and Lemmin U. (2004) Influence of coherent flow structures on the dynamics of suspended sediment transport in open-channel flow, Journal of Hydraulic Engineering, 1077–1088.
• 5. Da Silva A. M. F. (2006) On why and how river meander, Journal of Hydraulic Research, 44 (5), 579–590.
• 6. Holmes R. R. and Garcia M. H. (2008) Flow over bedforms in a large sand-bed river: a field investigation, Journal of Hydraulic Research, 46 (3), 322–333.
• 7. Jackson R. (1976) Sedimentological and fluid-dynamic implications of the turbulent bursting phenomenon in geophysical flows, Journal of Fluid Mechanics, 77, part 3, 531–560.
• 8. Kaftori D., Hetsroni G. and Bnerjee S. (1995) Particle behavior in the turbulent boundary layer II. Velocity and distribution profiles, Physics of Fluids, 7, 1107–1121.
• 9. Kline S. J. Reynolds W. C., Schraub F. A., Runstadler P. W. (1967) The structure of turbulent boundary layers, Journal of Fluid Mechanics, 30 (2), 741–773.
• 10. Lemmin U. and Rolland (1997) Acoustic Velocity profiler for laboratory and Field studies, Journal of Hydraulic Engineering, 123 (12), 1089–1097.
• 11. Lu S. S. and Willmarth W. W. (1973) Measurements of the Reynolds stress in a turbulent layer, Journal of Fluid Mechanics, 60 (3), 481–511.
• 12. Nelson J. M., Shreve R. L., Mclean S., Drake T. G. (1995) Role of near-bed turbulence structure in bed load transport and bed form mechanics, Water Resources Research, 31 (5), 2071–2086.
• 13. Nezu I. and Nakagawa H. (1993) Turbulence on open channel flows, A. A. Balkema Publishers, Rotterdam, the Netherlands.
• 14. Nezu I. and Rodi W. (1986) Open-channel flow measurements with a laser Doppler anemometer, Journal of Hydraulic Engineering, ASCE, 112, 335–355.
• 15. Nino Y. and Garcia M. H. (1996)Experiments on particle-turbulence interactions in the near-wall region of an open channel flow: implications for sediment transport, Journal of Fluid Mechanics, 326, 285–319.
• 16. Pope S. B. (2000) Turbulent flows, Cambridge University Press.
• 17. Rashidi M., Hetsroni G. and Banerjee S. (1990) Particle-turbulence interaction in a boundary layer, International Journal of Multiphase Flow, 16 (6), 935–949.
• 18. Shen W. and Lemmin U. (1999) Application of an acoustic particle flux profiler in particle-laden open-channel flow, Journal of Hydraulic Research, 37, 407–419.
• 19. Shvidchenko A. B. and Pender G. (2001) Macroturbulent structure of open-channel flow over gravel beds, Water Resources Research, 37 (3), 709–719.
• 20. Termini D. (2005) Experimental investigation on the horizontal turbulence and the bed deformation: preliminary results, CD-Proceeding International Symposium on Stochastic Hydraulics – IAHR Congress, 23–24 May, Nijmegen – The Netherlands.
• 21. Termini D. and Lo Re C. (2006) Analysis of the relation between the flow “horizontal” turbulence and the bed deformation, Proceeding International Symposium on sediment Dynamics and the Hydromotphology of Fluvial Systems – Dundee (Scotland) 3–7 July, 73–79.
• 22. Termini D. and Sammartano V. (2007) Analysis of the role of turbulent structure in bed-forms formation in a rectilinear flume, 32nd Congress of IAHR, “Harmonizing the Demands of Art and Nature in Hydraulics” – Venice, Italy 1–6 July.
• 23. Utami T. and Ueno T. (1991) Experimental Study on the Compound meandering Channel Flow using Flow Visualization and picture processing, Journal of Hydroscience and Hydraulic Engrg., 9 (1), 1–10.
• 24. Yalin M. S. (1992) River Mechanics, Pergamon Press, London.
• 25. Yalin M. S. and da Silva A. F. (2001) Fluvial Processes, IAHR Monograph, Delft, The Netherlands.