Flow turbulence over mobile gravel-bed: spectral scaling and coherent structures

• Autorzy: Nikora V.
• Języki publikacji: EN

Abstrakty

EN

The turbulence structure of high Reynolds number, quasi-2-D flow with a weakly mobile gravel bed is considered, with particular focus on velocity spectra and bursting events from quadrant analysis. A four-range scaling model for velocity auto-spectra and co-spectra is discussed and tested. It is suggested that eddy clusters revealed using quadrant analysis contribute to the energy production, low wave -number region in velocity spectra, while individual bursting events contribute to the "-1" scaling region of intermediate wave numbers where energy production and cascade energy transfer co-exist. Possible relations between spectral scaling and coherent structures are briefly discussed.

Słowa kluczowe

EN

open channel flow; gravel-bed rivers; turbulence; coherent structures

• Wydawca: Instytut Geofizyki PAN
• Czasopismo: Acta Geophysica Polonica
• Rocznik: 2005
• Tom: Vol. 53, nr 4
• Strony: 539--552
• Opis fizyczny: Bibliogr. 29 poz.

Twórcy

autor

Nikora V.

• National Institute of Water and Atmospheric Research, PO Box 8602, Christchurch, New Zealand,

Bibliografia

• Antonia, R.A., and M.R. Raupach, 1993: "Spectral scaling in high Reynolds number laboratory boundary layer", Boundary-Layer Meteorology 65, pp. 289-306.
• Bennett, S.J., J.S. Bridge and J.L. Best, 1998: "Fluid and sediment dynamics of upper stage plane beds", J. Geophys. Res. 103 (CI), pp. 1239-1274.
• Campbell, L., I. McEwan, V. Nikora, D. Pokrajać and M. Gallagher, 2005: "Bed-load effects on hydrodynamics of rough-bed open-channel flows", J. Hydraul. Eng. ASCE 131 (7), pp. 576-585.
• Grinvald, D.I., and V.I. Nikora, 1988, River Turbulence, Hydrometeo., Leningrad (in Russian).
• Guckenheimer J., 1986: "Strange attractors in fluids: another view", Ann. Rev. Fluid Mech. 18, pp. 15-31.
• Gust, G., and J.B. Southard, 1983: "Effects of weak bed load on the universal law of the wall", J. Geophys. Res. 88 (CIO), pp. 5939-5952.
• Katul, G., and C-R. Chu, 1998: "A theoretical and experimental investigation of energy containing scales in the dynamic sublayer of boundary-layer flows", Boundary-Layer Meteorology 86, pp. 279-312.
• Luchik, T.S., and W.G. Tiederman, 1987: "Timescale and structure of ejections and bursts in turbulent channel flows", J. Fluid Mech. 174, pp. 529-552.
• McComb, W.D., 1991, 77ie Physics of Fluid Turbulence, Clarendon Press, Oxford.
• Monin, A.S., and A.M. Yaglom, 1975, Statistical Fluid Mechanics: Mechanics of Turbulence, vol. 2, MIT Press, Boston, Mass.
• Nelkin, M., 1994: "Universality and scaling in fully developed turbulence". Advances in Physics 43 (2), pp. U3-m.
• Nezu, I., and H. Nakagawa, 1993, Turbulence in Open-Channel Flows, Balkema, Rotterdam.
• Nikora, V.I., 1999: "Origin of the "-1" spectral law in wall-bounded turbulence", Phys. Rev. Lett. 83, pp. 734-737.
• Nikora, V.I., and D.G. Goring, 1998: "Spectral scaling for gravel-bed open-channel flows. In; Stochastic Models of Hydrological Processes and their Applications to Problems of Environmental Preservation, NATO Advanced Research Workshop, pp. 239-245, Water Problems Institute, Moscow.
• Nikora, V.I., and D.G. Goring, 1999: "Effects of bed mobility on turbulence structure", NIWA Internal Report No. 48, pp. 48, NIWA, Christchurch.
• Nikora, V.I., and D.G. Goring, 2000a: "Flow turbulence over fixed and weakly mobile gravel beds", J. Hydraul. Eng. ASCE 126 (9), pp. 679-690.
• Nikora, V.I., and D.G. Goring, 2000b: "Eddy convection velocity and Taylor's hypothesis 'frozen' turbulence in a rough-bed open-channel flow", J. HydroScience and Hydraid. Eng. JSCE IS (2), pp. 15-91.
• Nikora, V.I., and G.M. Smart, 1997: "Turbulence characteristics of New Zealand gravel-bed rivers", J. Hydraul. Eng. ASCE 123 (9), pp. 764-773.
• Perry, A.E., and M.S. Chong, 1982: "On the mechanism of wall turbulence, J. Fluid Meek 119, pp. 173-217.
• Perry, A.E., and J.D. Li, 1990: "Experimental support for the attached-eddy hypothesis in zero-pressure-gradient turbulent boundary layers", J. Fluid Mech. 218, pp. 405-438.
• Perry, A.E., S.M. Henbest and M.S. Chong, 1986: "A theoretical and experimental study of wall turbulence", J. Fluid Mech. 165, pp. 163-199.
• Perry, A.E., K.L. Lim and S.M. Henbest, 1987: "An experimental study of the turbulence structure in smooth- and rough-wall boundary layers", J. Fluid Mech. 177, pp. 437-466.
• Raupach, M.R., R.A. Antonia and S. Rajagopalan, 1991: "Rough-wall turbulent boundary layers", Appl. Mech. Rev. 44 (1), pp. 1-25.
• Song, T., W.H. Graf and U. Lemmin, 1994: "Uniform flow in open channels with movable gravel bed", J. Hydraul. Res. IAHR 32 (6), pp. 861-876.
• Sukhodolov, A.N., M. Thiele and H. Bungartz, 1998: "Turbulence structure in a river reach with sand bed". Water Resources Res. 34 (5), pp. 1317-1334.
• Taylor, G., 1938: "The spectrum of turbulence", Proc. Roy. Soc. A164 (919), pp. 476-490.
• Whiting, P.J, and W.E. Dietrich, 1990: "Boundary shear stress and roughness over mobile alluvial beds", J. Hydraul. Eng. ASCE 116 (12), pp. 1495-1511.
• Williams, J.J., P.D. Thome and A.D. Heathershaw, 1989: "Measurements of turbulence in the benthic boundary layer over a gravel bed", Sedimentology 36, pp. 959-971.
• Yaglom, A.M., 1993: "Similarity laws for wall turbulent flows: their limitations and generalizations". In: Th. Dracos and A. Tsinober (eds.). New Approaches and Concepts in Turbulence, pp. 7-27, Birkhauser Verlag, Basel.