Resumen
In wave flumes an onshore boundary layer current is present that is not present in oscillating flow tunnels. We investigate numerically the hypothesis that this streaming explains the measured increase of onshore directed sediment transport in flumes over tunnels. In the formulation and validation of the model special attention has been given to the wave-generated net current profile. From model experiments we conclude that the additional current indeed contributes to onshore transport, but can not be the full explanation of the measured differences in transport rates. Other contributing mechanisms are the amplification/reduction of the fall velocity by vertical sediment advection (only relevant for fine grains) and the amplification/reduction of the concentration at maximum onshore/offshore velocity by intra-wave gradients in horizontal sediment flux. The latter contributes, for the investigated cases, to onshore transport with comparable order as the boundary layer current. These conclusions are relevant for further development of parameterizations of wave-induced sediment transport for morphodynamic models.Referencias
Bosboom. J. and Klopman. G. 2000. 1DV simulation of wave current interaction. Proc. 27th ICCE, ASCE, 2452-2466.
Davies, A.G. and Li, Z. 1997. Modelling sediment transport beneath regular symmetrical and asymmetrical waves above a plane bed. Continental Shelf Research, 17(5), 555-582.http://dx.doi.org/10.1016/S0278-4343(96)00048-9
Dohmen-Janssen, C.M., 1999. Grain size influence on sediment transport in oscillatory sheet flow -phase lags and mobile-bed effects, PhD-Thesis, Delft University of Technology, Delft, 246 pp.
Dohmen-Janssen, C.M. and Hanes, D.M., 2002. Sheet flow dynamics under monochromatic nonbreaking waves. Journal of Geophysical Research, 107(C10) http://dx.doi.org/10.1029/2001JC001045
Dohmen-Janssen, C.M., Kroekenstoel, D.F., Hassan, W.N., Ribberink, J.S., 2002. Phase lags in oscillatory sheet flow: experiments and bed load modelling. Coastal Enigneering, 46, 61-87 http://dx.doi.org/10.1016/S0378-3839(02)00056-X
Dohmen-Janssen, C.M., and Hanes, D.M., 2005, Sheet flow and suspended sediment due to wave groups in a large wave flume, Continental Shelf Research, 25, 333-347 http://dx.doi.org/10.1016/j.csr.2004.10.009
Elgar, S., and 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
Hassan, W.N. and Ribberink J.S., 2010, Modelling of sand transport under wave-generated sheet flows with a RANS diffusion model; Coastal Engineering, 57, 19-29 http://dx.doi.org/10.1016/j.coastaleng.2009.08.009
Henderson, S.M., Allen, J.S., Newberger, P.A., 2004. Nearshore sandbar migration predicted by an eddy-diffusive boundary layer model. Journal of Geophysical Research, 109(C06024).
Hoefel, F. and Elgar, S., 2003. Wave-induced sediment transport and sandbar migration. Science, 299, 1885-1887. PMid:12649479 http://dx.doi.org/10.1126/science.1081448
Holmedal, L.E. and Myrhaug, D., 2009, Wave-induced steady streaming, mass transport and net sediment transport in rough turbulent ocean bottom boundary layers, Continental Shelf Research, 1. 7, 911-926 http://dx.doi.org/10.1016/j.csr.2009.01.012
Klopman, G. 1994. Vertical structure of the flow due to waves and currents. Progress report, Delft Hydraulics, H840.32, Part 2.
Longuet-Higgins, M.S., 1953, Mass transport in water waves, Philos. Trans. R. Soc. London, Ser. A, 245, 535- 581.
Longuet-Higgins, M.S., 1958, The mechanics of the boundary-layer near the bottom in a progressive wave". Proc. 6th ICCE, ASCE, 184-193.
O'Donoghue, T. and Wright, S., 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. and Wright, S., 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
Ribberink, J.S. and Al-Salem, A.A., 1994. Sediment transport in oscillatory boundary layers in cases of rippled beds and sheet flow. Journal of Geophysical Research, 99(C6), 12707 - 12727. http://dx.doi.org/10.1029/94JC00380
Ribberink, J.S. and Al-Salem, A.A., 1995. Sheet flow and suspension of sand in oscillatory boundary layers. Coastal Engineering, 25, 205 - 225. http://dx.doi.org/10.1016/0378-3839(95)00003-T
Ribberink, J.S. and Chen, Z., 1993. Sediment transport of fine sand under asymmetric oscillatory flow. Experimental study in the large oscillating water tunnel of Delft Hydraulics, Delft University of Technology, Delft Hydraulics, Delft, The Netherlands.
Richardson, J.F. & Zaki, W.N. 1954 Sedimentation and fluidization. Trans. Inst. Chem. Engng, 32, 35-53.
Rijn, L.C. van, 1993. Principles of sediment transport in rivers, estruaries and coastal seas. Aqua Publ. (The Netherlands) PMCid:1005200
Ruessink, B.G., van den Berg, T.J.J., van Rijn, L.C., 2009. Modeling sediment transport beneath skewed-asymmetric waves above a plane bed. Journal of Geophysical Research, 114(C11021)
Schretlen, J.L.M., Ribberink J.S.,O'Donoghue, T., 2010. Boundary layer flow and sand transport under full scale surface waves, Proc. 32th ICCE, ASCE
Trowbridge, J. and Madsen, O. S., 1984, Turbulent wave boundary layers. 2. Second-order theory and mass transport. Journal of Geophysical Research, 89(C5), 7999-8007. http://dx.doi.org/10.1029/JC089iC05p07999
Uittenbogaard, R.E., 2000. 1DV simulation of wave current interaction. Proc. 27th ICCE, ASCE, 255-268
Werf, J. van der, Schretlen, J., Ribberink, J., O'Donoghue, T., 2009. Database of full-scale laboratory experiments on wave-driven sand transport processes. Coastal Engineering., 56, 726-732http://dx.doi.org/10.1016/j.coastaleng.2009.01.008
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
Wright, S. and O'Donoghue, T., 2002. Total sediment transport rate predictions in wave current sheet flow with graded sand. Oscillatory flow tunnel experiments at Aberdeen University, University of Aberdeen, Aberdeen, UK.
Zyserman, J.A. and Fredsoe, J., 1994. Data analysis of bed concentration of suspended sediment. Proc.Am. Soc. Civ. Eng., Journal of Hydraulic Engineering, 120(9): 1021-1042.