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Turbulent open-channel flows with variable depth across the channel

Published online by Cambridge University Press:  26 April 2006

Koji Shiono
Affiliation:
Department of Civil Engineering, University of Bradford, Bradford BD7 1DP, West Yorkshire, UK
Donald W. Knight
Affiliation:
School of Civil Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK

Abstract

The flow of water in straight open channels with prismatic complex cross-sections is considered. Lateral distributions of depth-mean velocity and boundary shear stress are derived theoretically for channels of any shape, provided that the boundary geometry can be discretized into linear elements. The analytical model includes the effects of bed-generated turbulence, lateral shear turbulence and secondary flows. Experimental data from the Science and Engineering Research Council (SERC) Flood Channel Facility are used to illustrate the relative importance of these three effects on internal shear stresses. New experimental evidence concerning the spatial distribution of Reynolds stresses τyx and τzx is presented for the particular case of compound or two-stage channels. In such channels the vertical distributions of τzx are shown to be highly nonlinear in the regions of strongest lateral shear and the depth-averaged values of τyx are shown to be significantly different from the depth mean apparent shear stresses. The importance of secondary flows in the lateral shear layer region is therefore established. The influence of both Reynolds stresses and secondary flows on eddy viscosity values is quantified. A numerical study is undertaken of the lateral distributions of local friction factor and dimensionless eddy viscosity. The results of this study are then used in the analytical model to reproduce lateral distributions of depth-mean velocity and boundary shear stress in a two stage channel. The work will be of interest to engineers engaged in flood channel hydraulics and overbank flow in particular.

Type
Research Article
Copyright
© 1991 Cambridge University Press

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References

Ackebs, P. & White, W. R., 1973 Sediment transport: new approach and analysis. J. Hydraul. Div. ASCE 99, (HY11), pp. 20412060.Google Scholar
Elliott, S. C. A. & Sellin, R. H. J. 1990 SERC Flood Channel Facility: Skewed flow experiments. J. Hydraul. Res. 28, 197214.Google Scholar
Garde, R. J. & Raju, K. G. Ranga 1977 Mechanics of Sediment Transportation and Alluvial Stream Problems. New Delhi: Wiley Eastern.
Kawahara, H. & Tamai, N., 1988 Numerical calculations of turbulent flows in compound channel with an algebraic stress turbulence model. Proc. 3rd Intl Symp. on Refined Flow Modelling and Turbulence Measurements, Tokyo, Japan, July, pp. 917.Google Scholar
Keller, R. J. & Rodi, W., 1988 Prediction of flow characteristics in main channel flood plain flows. J. Hydraul. Res. 26, 425441.Google Scholar
Knight, D. W. & Demetriou, J. D., 1983 Flood plain and main channel flow interaction. J. Hydraul. Engng ASCE 109, 10731092.Google Scholar
Knight, D. W., Demeteiou, J. D. & Hamed, M. E., 1984 Stage discharge relationships for compound channels. Proc. 1st Intl Conf. on Channels and Channel Control Structures (ed. K. V. H. Smith), pp. 4.214.35. Springer.
Knight, D. W. & Hamed, M. E., 1984 Boundary shear in symmetrical compound channels. J. Hydraul. Engng ASCE 110, 14121430.Google Scholar
Knight, D. W. & Lai, C. J., 1986 Compound duct flow data, vol. 10. University of Birmingham, Dept. of Civil Engng Rep. pp. 173.
Knight, D. W., Samuels, P. G. & Shiono, K., 1990 River flow simulation: research and developments. J. Inst. Water Environ. Management 4, pp. 163175.Google Scholar
Knight, D. W. & Sellin, R. H. J. 1987 The SERC Flood Channel Facility. J. Int. Water Environ. Management 1, 198204.Google Scholar
Knight, D. W. & Shiono, K., 1990 Turbulence measurements in a shear layer region of a compound channel. J. Hydraul. Res. 28, 175196.Google Scholar
Knight, D. W., Shiono, K. & Pirt, J., 1989 Prediction of depth mean velocity and discharge in natural rivers with overbank flow. Intl Conf. Hydraulic and Environmental Modelling of Coastal, Estuarine and River Waters, Bradford University, England (ed R. A. Falconer, P. Goodwin & G. S. Matthew), pp. 419428. Gower Technical Press.
Krishnappan, B. G. & Lau, Y. L., 1986 Turbulence modelling of flood plain flows. J. Hydraul. Engng, ASCE 112, 251266.Google Scholar
Lai, C. J. & Knight, D. W., 1988 Distributions of streamwise velocity and boundary shear stress in compound ducts. Proc. 3rd Intl Symp. on Refined Flow Modelling and Turbulence Measurements, Tokyo, Japan, July, pp. 527536.Google Scholar
Larsonr, R.: 1988 Numerical simulation of flow in compound channels. Proc. 3rd Intl Symp. On Refined Flow Modelling and Turbulence Measurements, Tokyo, Japan, July, pp. 527536.Google Scholar
Lau, L. & Krishnappan, B. G., 1977 Transverse dispersion in rectangular channels. J. Hydraul. Div. ASCE 103 (HY10), 11731189.Google Scholar
Myers, R. C. & Elsawy, E. M., 1975 Boundary shear in channel with flood plain. J. Hydraul. Engng, ASCE 7, 933947.Google Scholar
Myers, W. R. C.: 1978 Momentum transfer in a compound channel. J. Hydraul. Res. 16, 139150.Google Scholar
Myers, W. R. C. & Brennan, E. K. 1990 Flow resistance in compound channels. J. Hydraul. Res. 28, 141155.Google Scholar
Nakayama, A., Chow, W. L. & Sharma, D., 1983 Calculation of fully developed turbulent flows in ducts of arbitrary cross-section. J. Fluid Mech. 128, 199217.Google Scholar
Naot, D. & Rodi, W., 1982 Calculation of secondary currents in channel flow. J. Hydraul. Div. ASCE 108 (HY8), 948968.Google Scholar
Nezu, I. & Rodi, W., 1986 Open channel flow measurements with a laser doppler anemometer. J. Hydraul. Engng, ASCE 112, 335355.Google Scholar
Nokes, R. I. & Wood, I. R., 1987 Lateral turbulent dispersion in open channel flow. Proc. 22nd Biennial Congress, IAHR, Lausanne, pp. 233338.Google Scholar
Nokes, R. I. & Wood, I. R., 1988 Vertical and lateral turbulent dispersion: some experimental results. J. Fluid Mech. 187, 373394.Google Scholar
Patel, V. C.: 1965 Calibration of the Preston tube and limitations on its use in pressure gradients. J. Fluid Mech. 23, 185195.Google Scholar
Shiono, K. & Knight, D. W., 1988 Two dimensional analytical solution for a compound channel. Proc. 3rd Intl Symp. on Refined Flow Modelling and Turbulence Measurements, Tokyo, Japan, July (ed. Y. Iwasa, N. Tamai & A. Wada), pp. 503510.
Shiono, K. & Knight, D. W., 1989 Vertical and transverse measurements of Reynolds stress in a shear region of a compound channel. Proc. 7th Intl Symp. on Turbulent Shear Flows, Stanford, USA, August, pp. 28.1.128.1.6.Google Scholar
Wormleaton, P. R.: 1988 Determination of discharge in compound channels using the dynamic equation for lateral velocity distribution. Proc. Intl Conf. on Fluvial Hydraulics, Budapest.Google Scholar
Wormleaton, P. R., Allen, J. & Hadjipanos, P., 1982 Discharge assessment in compound channel flow. J. Hydraul. Div. ASCE 108 (HY9), 975993.Google Scholar
Wormleaton, P. R. & Merrett, D., 1990 An improved method of calculation for steady uniform flow in prismatic main channel/flood plain sections. J. Hydraul. Res. 28, 157174.Google Scholar
Younis, B. A. & Abdellatif, O. E., 1989 Modelling of sediment transport in rectangular ducts with a two-equation model of turbulence. Proc. Intl Symp. on Sediment Transport Modelling, A8CE, New Orleans, August, pp. 197202.Google Scholar
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