Abstract
Experiments have been conducted to investigate the sheetflow sediment transport of uniform sand under asymmetric oscillatory flows in combination with relatively strong opposite currents. Two kinds of nearshore waves were performed, namely, velocity asymmetric waves and acceleration asymmetric waves. Image analysis technique is utilized to study major influences of wave shapes and current through observing the instantaneous sheetflow layer thickness. Maximum sheetflow layer thickness was formulated and incorporated to an enhanced Watanabe and Sato's formulation. The new conceptual model is examined its validity for a wide range of experimental conditionsReferences
Ahmed, A. S. M. & S. Sato (2003) A Sheetflow Transport Model for Asymmetric Oscillatory Flows: Part I: Uniform Grain Size Sediments Coastal Engineering Journal (JSCE), 45, 321-337
Da Silva, P. A., A. Temperville & F. Seabra Santos (2006) Sand transport under combined current and wave conditions: A semi-unsteady, practical model. Coastal Engineering, 53, 897-913. http://dx.doi.org/10.1016/j.coastaleng.2006.06.010
Dibajnia, M., T. Moriya & A. Watanabe (2001) A representative wave model for estimation of nearshore local transport rate. Coastal Engineering Journal (JSCE), 43, 38.http://dx.doi.org/10.1142/S0578563401000256
Dibajnia, M. & A. Watanabe. 1992. Sheet flow under nonlinear waves and currents. In Proceedings 23rd International Conference on Coastal Engineering, 2015-2028. ASCE.
Dohmen-Janssen, C. M. 1999. Grain size influence on sediment transport in oscillatory sheet flow: phase lags and mobile bed effects. In 246. Delft University of Technology.
Dohmen-Janssen, C. M., W. N. Hassan & J. S. Ribberink (2001) Mobile-bed effects in oscillatory sheet flow. J. Geophys. Res., 106.
Dohmen-Janssen, C. M., D. F. Kroekenstoel, W. N. Hassan & J. S. Ribberink (2002) Phase lags in oscillatory sheet flow: experiments and bed load modelling. Coastal Engineering, 46, 61-87. http://dx.doi.org/10.1016/S0378-3839(02)00056-X
Elgar, S. & R. T. Guza (1985) Observations of bispectra of shoaling surface gravity waves. Journal of Fluid Mechanics, 161, 425-448. http://dx.doi.org/10.1017/S0022112085003007
Fredsøe, J. & R. Deigaard. 1992. Mechanics of Coastal Sediment Transport World Scientific, 392pp.
Horikawa, K., A. Watanabe & S. Katori. 1982. Sediment transport under sheetflow conditions. In Proceedings 18th International Conference on Coastal Engineering, 1335-1352. ASCE.
Mina, K. M. & S. Sato (2004) A transport model for sheetflow based on two-phase flow. Coastal Engineering Journal (JSCE), 46, 329-367. http://dx.doi.org/10.1142/S0578563404001099
Nielsen, P. 1992. Coastal Bottom boundary layers and sediment transport. World Scientific.
O'Donoghue, T. & S. Wright (2004a) Concentrations in oscillatory sheet flow for well sorted and graded sands. Coastal Engineering, 50, 117-138. http://dx.doi.org/10.1016/j.coastaleng.2003.09.004
O'Donoghue, T. & S. Wright (2004b) Flow tunnel measurements of velocities and sand flux in oscillatory sheet flow for well-sorted and graded sands. Coastal Engineering, 51, 1163-1184.http://dx.doi.org/10.1016/j.coastaleng.2004.08.001
Pruszak, Z., P. V. Ninh, M. Szmytkiewicz, N. M. Hung & R. Ostrowski (2005) Hydrology and morphology of two river mouth regions(temperate Vistula Delta and subtropical Red River delta). Oceanologia, 47, 365-385.
Ribberink, J. S. (1998) Bed-load transport for steady flows and unsteady oscillatory flows. Coastal Engineering, 34, 59-82.http://dx.doi.org/10.1016/S0378-3839(98)00013-1
Ribberink, J. S. & A. A. Al-Salem (1994) Sediment transport in oscillatory boundary layers in cases of rippled beds and sheet flow. J. Geophys. Res., 99.
Ribberink, J. S. & Z. Chen. 1993. Sediment transport of fine sand under asymmetric oscillatory flow. Report H840, Part VII, Delft Hydraulics, The Netherlands.Sato, S., M. B. Kabiling & H. Suzuki (1992) Prediction of near-bottom velocity history by a nonlinear dispersive wave model. Coastal Engineering in Japan, 35, 67-82.
Sleath, J. F. A. (1999) Conditions for plug formation in oscillatory flow. Continental Shelf Research,19, 1643-1664. http://dx.doi.org/10.1016/S0278-4343(98)00096-X
Swart, D. H. 1974. Offshore sediment transport and equilibrium beach profiles. The Netherlands, Delft Hydraulics.
Van Rijn, L. (1993) Principles of sediment transport in rivers, estuaries and coastal seas. 715.
Watanabe, A. & S. Sato. 2004. A sheet-flow transport rate formula for asymmetric, forward-leaning waves and currents. In Proceedings 29th International Conference on Coastal Engineering, 1703-1714. ASCE.
Wilson, K. C. (1989) Friction of wave-induced sheet flow. Coastal Engineering, 12, 371-379.http://dx.doi.org/10.1016/0378-3839(89)90013-6
Wilson, K. C., J. S. Andersen & J. K. Shaw (1995) Effects of wave asymmetry on sheet flow. Coastal Engineering, 25, 191-204.http://dx.doi.org/10.1016/0378-3839(95)00006-W