THRESHOLDS OF UPPER-STAGE PLANE BED REGIME FOR INTENSE BED LOAD IN OPEN CHANNEL
DOI:
https://doi.org/10.14311/CEJ.2016.02.0006Keywords:
Sediment transport, two-phase flow, bed formsAbstract
Results are discussed of laboratory experiments on criteria determining the transition between the regime of dunes and the upper stage plane bed (UPB) regime and the transition between the UPB regime and the regime of wavy flow. The experiments were carried for 3 fractions of plastic material and two fractions of glass beads in a broad range of flow conditions (different discharges of water and solids and longitudinal bed slopes) in a tilting flume.
The experiments reveal that, contrary to expectations, a constant value of the Shields parameter is not an appropriate criterion for the transition between the dune regime and the UPB regime. Instead, the criterion seems to be well represented by a constant value of the longitudinal bed slope. The transition between the UPB regime and the wavy regime is found at a constant value of the densimetric Froude number. Relatively high values of Froude number at the threshold are due primarily to the presence of the collisional transport layer which protects the bed from an influence of undulating water surface.
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References
Matoušek V. et al., 2016. Experimental evaluation of bed friction and solids transport in steep flume. The Canadian Journal of Chemical Engineering, vol. 94, No. 6, 1076 –1083.
Berzi D., Fraccarollo L., 2013. Inclined collisional sediment transport. Physics of Fluids, vol. 25, No. 10, 10.1063/1.4823857,
Southard, J.B. and Boguchwal, L.A., 1990. Bed configurations in steady unidirectional flows: Part 2. 1229 Synthesis of flume data, Journal of Sedimentary Petrology, vol. 60. 658–679.
Van Rijn, L.C., 1989. Handbook of Sediment Transport by Current and Waves (Delft Hydraulics)
Zrostlík Š. et al., 2014. One-dimensional velocity profiles in open-channel flow with intense transport of coarse sediment In Proceedings of 9th International Conference on Experimental Fluid Mechanics, EFM (EPJ Web of Conferences)
Matoušek V. et al., 2015. Experimental investigation of structure of open-channel flow with intense transport of sediment, Journal of Hydrology and Hydromechanics, vol. 63, No. 4. 318 – 326.
Wilson K.C. et al., 2006. Slurry Transport using Centrifugal Pumps, Third Edition, (Springer). 432.
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