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Experiments on particle—turbulence interactions in the near–wall region of an open channel flow: implications for sediment transport

Published online by Cambridge University Press:  26 April 2006

Y. Ninto
Affiliation:
Hydrosystems Laboratory, Department of Civil Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
M. H. Garcia
Affiliation:
Hydrosystems Laboratory, Department of Civil Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA

Abstract

A high-speed video system was used to study the interaction between sediment particles and turbulence in the wall region of an open channel flow with both smooth and transitionally rough beds. In smooth flows, particles immersed within the viscous sublayer were seen to accumulate along low-speed wall streaks; apparently due to the presence of quasi-streamwise vortices in the wall region. Larger particles did not tend to group along streaks, however their velocity was observed to respond to the streaky structure of the flow velocity in the wall region. In transitionally rough flows particle sorting was not observed. Coherent flow structures in the form of shear layers typically observed in the near-wall region interacted with sediment particles lying on the channel bottom, resulting in the particles being entrained into suspension. Although there has been some speculation that this process would not be effective in entraining particles totally immersed in the viscous sublayer, the results obtained demonstrate the opposite. The entrainment mechanism appears to be the same independent of the roughness condition of the bottom wall, smooth or transitionally rough. In the latter case, however, hiding effects tend to preclude the entrainment of particles with sizes finer than that of the roughness elements. The analysis of particle velocity during entrainment shows that the streamwise component tends to be much smaller than the local mean flow velocity, while the vertical component tends to be much larger than the local standard deviation of the vertical flow velocity fluctuations, which would indicate that such particles are responding to rather extreme flow ejection events.

Type
Research Article
Copyright
© 1996 Cambridge University Press

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References

Ashida, K. & Fujita, M. 1986 Stochastic model for particle suspension in open channels. J. Hydrosci. Hydr. Engng 4, 2146.Google Scholar
Bagnold, R. A. 1966 An approach to the sediment transport problem for general physics. Geological Survey Professional Paper 422–1, Washington, DC.
Bark, F. 1975 On the wave structure of the wall region of a turbulent boundary layer. J. Fluid Mech. 70, 229250.Google Scholar
Batchelor, G. K. 1964 Diffusion from sources in a turbulent boundary layer. In Arch. Mech. Stosowanej 3 (16), 661670.Google Scholar
Best, J. 1992 On the entrainment of sediment and initiation of bed defects: insights from recents developments within turbulent boundary layer research. Sedimentology 39, 797811.CrossRefGoogle Scholar
Blackwelder, R. F. 1988 Coherent structures associated with turbulent transport. In Transport Phenomena in Turbulent Flows: Theory, Experiments, and Numerical Simulation (ed. M. Hirata & N. Kasagi), pp. 6988.
Browand, F. K. & Plocher, D. A. 1985 Image processing for sediment transport. In Proc. 21st Congress IAHR, Melbourne, Australia, pp. 814.
Cermak, J. E. 1963 Lagrangian similarity hypothesis applied to diffusion in turbulent shear flow. J. Fluid Mech. 15, 4963.Google Scholar
Clauser, F. H. 1956 The turbulent boundary layer. Adv. Appl. Mech. 4, 131.Google Scholar
Cleaver, J. W. & Yates, B. 1976 The effect of re-entrainment on particle deposition. Chem. Engng Sci. 31, 147151.Google Scholar
Dill, A. J. 1994 Video-based particle tracking velocimetry technique for measuring flow velocity in porous media. Masters Thesis, Dept. Civil Engng. Univ. of Illinois at Urbana-Champaign, Illinois.
Falco, R. E. 1991 A coherent structure model of the turbulent boundary layer and its ability to predict Reynolds number dependence. Phil. Trans. R. Soc. Lond. A 336, 103129.Google Scholar
García, M., López, F. & Niño, Y. 1995 Characterization of near-bed coherent structures in open channel flow using synchronized high-speed video and hot-film measurements. Exps. Fluids 19, 1628.Google Scholar
Grass, A. J. 1974 Transport of fine sand on a flat bed: turbulence and suspension mechanics. In Euromech 48, pp. 3334. Inst. Hydrodynamic and Hydraulic Engrg. Tech. Univ. Denmark.
Grass, A. J. 1971 Structural features of turbulent flow over smooth and rough boundaries. J. Fluid Mech. 50, 233255.Google Scholar
Grass, A. J., Stuart, R. J. & Mansour-Tehrani, M. 1991 Vortical structures and coherent motion in turbulent flow over smooth and rough boundaries. Phil. Trans. R. Soc. Lond. A 336, 3565.Google Scholar
Guezennec, Y. G., Piomeli, U. & Kim, J. 1989 On the shape and dynamics of wall structures in turbulent channel flow. Phys. Fluids A 1, 764766.Google Scholar
Hassan, Y. A., Blanchat, T. K., Seeley, C. H. & Canaan, R. E. 1992 Simultaneous velocity measurements of both components of a two-phase flow using Particle Image Velocimetry. Intl J. Multiphase Flow 8, 371395.Google Scholar
Hetsröni, G. 1991 The effect of particles on the turbulence in a boundary layer. In Two Phase Flow (ed. M. Rocco), Chap. 8. Butterworth.
Hinze, J. O. 1971 Turbulent fluid and particle interaction. Progress Heat Mass Transfer 6, 433452.Google Scholar
Jackson, R. G. 1976 Sedimentological and fluid dynamics implications of the turbulent bursting phenomenon in geophysical flows. J. Fluid Mech. 77, 531560.Google Scholar
Jimenez, J., Moin, P., Moser, R. & Keefe, L. 1988 Ejection mechanisms in the sublayer of a turbulent channel. Phys. Fluids 31, 13111313.Google Scholar
Kaftori, D., Hetsroni, G. & Banerjee, S. 1995a Particle behaviour in the turbulent boundary layer I. Motion, deposition, and entrainment. Phys. Fluids 7, 10951106.Google Scholar
Kaftori, D., Hetsroni, G. & Banerjee, S. 19956 Particle behaviour in the turbulent boundary layer II. Velocity and distribution profiles. Phys. Fluids 7 11071121.Google Scholar
Kim, H. T., Kline, S. J. & Reynolds, W. C. 1971 The production of turbulence near a smooth wall in a turbulent boundary layer. J. Fluid Mech. 50, 133160.Google Scholar
Kline, S. J., Reynolds, W. C., Schraub, F. A. & Runstadler, P. W. 1967 The structure of turbulent boundary layers. J. Fluid Mech. 30, 741773.Google Scholar
Liu, Z., Landreth, C. C., Adrian, R. J. & Hanratty, T. J. 1991 Measurements in turbulent channel flow by high resolution Particle Image Velocimetry. Exps. Fluids 10, 301312.Google Scholar
Moin, P. & Kim, J. 1982 Numerical investigation of turbulent channel flow. J. Fluid Mech., 118, 341377.Google Scholar
Moin, P. & Spalart, P. R. 1989 Contributions of numerical simulation data bases to the physics, modelling, and measurement of turbulence. In Advances in Turbulence (ed. W. K. George & R. Arndt), pp. 1138. Hemisphere/Springer.
Nakagawa, H. & Nezu, I. 1977 Prediction of the contributions to the Reynolds stress from bursting events in open-channel flows. J. Fluid Mech. 80, 99128.Google Scholar
Nakagawa, H. & Nezu, I. 1981 Structure of space—time correlations of bursting phenomena in an open-channel flow. J. Fluid Mech. 104, 143.Google Scholar
Nezu, I. & Nakagawa, H. 1993 Turbulence in open-channel flows. In IAHR Monograph. A. A. Balkema, Rotterdam.
Niño, Y. 1995 Particle motion in the near-wall region of a turbulent open channel flow: implications for bedload transport by saltation and sediment entrainment into suspension. PhD Thesis. University of Illinois at Urbana-Champaign. Urbana, Illinois.
Niño, Y. & García, M. 1995 Threshold for particle entrainment into suspension. J. Hydraul. Engng ASCE (submitted).
Pedinotti, S., Mariotti, G. & Banerjee, S. 1992 Direct numerical simulation of particle behaviour in the wall region of turbulent flows in horizontal channels. Intl J. Multiphase Flow 18, 927941.Google Scholar
Perry, A. E. & Li, J. D. 1990 Experimental support for the attached-eddy hypothesis in zero-pressure-gradient turbulent boundary layers. J. Fluid Mech. 218, 405438.Google Scholar
Perry, A. E., Schofield, W. H. & Joubert, P. N. 1969 Rough wall turbulent boundary layers. J. Fluid Mech. 37, 383413.Google Scholar
Rashidi, M., Hetsroni, G. & Banerjee, S. 1990 Particle-turbulence interaction in a boundary layer. Intl J. Multiphase Flow 16, 935949.Google Scholar
Raupach, M. R. 1981 Conditional statistics of Reynolds stress in rough-wall and smooth-wall turbulent boundary layers. J. Fluid Mech. 108, 363382.Google Scholar
Raupach, M. R., Antonia, R. A. & Rajagopalan, S. 1991 Rough-wall turbulent boundary layers. Appl. Mech. Rev. 44, No. 1.Google Scholar
Robinson, S. K. 1990 Kinematics of turbulent boundary layer structure. PhD dissertation. Standford University.
Robinson, S. K. 1991 Coherent motions in the turbulent boundary layer. Ann. Rev. Fluid Mech. 23, 601639.Google Scholar
Schlichting, H. 1968 Boundary-Layer Theory. McGraw-Hill.
Schmid, A. 1985 Wandnahe turbulente bewegungsabläufe und ihre bedeutung für die riffelbildung. Institute für Hydromechanik und Wasserwirtschaft, R 22–85. ETH, Zürich.
Smith, C. R. & Schwartz, S. P. 1983 Observation of streamwise rotation in the near-wall region of a turbulent boundary layer. Phys. Fluids 26 641652.Google Scholar
Sumer, B. M. & Deigaard, R. 1981 Particle motions near the bottom in turbulent flow in an open channel. Part 2. J. Fluid Mech. 109, 311337.Google Scholar
Sumer, B. M. & Oguz, B. 1978 Particle motions near the bottom in turbulent flow in an open channel. J. Fluid Mech. 86, 109127.Google Scholar
Sutherland, A. J. 1967 Proposed mechanism for sediment entrainment by turbulent flows. J. Geophys. Res. 72, 191198.Google Scholar
Urushihara, T., Meinhart, C. D. & Adrian, R. J. 1993 Investigation of the logarithmic layer in pipe flow using Particle Image Velocimetry. In Near-Wall Turbulent Flows (ed. R. M. C. So, C. G. Speziale & B. E. Launder). Elsevier.
Wei, T. & Willmarth, W. 1991 Examination of v-velocity fluctuations in a turbulent channel flow in the context of sediment transport. J. Fluid Mech. 233, 241252.Google Scholar
Wells, M. R. & Stock, D. E. 1983 The effects of crossing trajectories on the dispersion of particles in a turbulent flow. J. Fluid Mech. 136, 3162.Google Scholar
Yen, B. C. 1992 Sediment fall velocity in oscillating flow. Water Resour. and Environ. Engrg. Res., Rep. 11. Dept. of Civil Engng. University of Virginia.
Yung, B. P. K., Merry, H. & Bott, T. R. 1988 The role of turbulent bursts in particle re-entrainment in aqueous systems. Chem. Engng Sci. 44, 873882.Google Scholar
Zhuang, Y., Wilson, J. D. & Lozowski, E. P. 1989 A trajectory-simulation model for heavy particle motion in turbulent flow. J. Fluids Engng 111, 492494.Google Scholar