TY - JOUR
T1 - Parameterization of near-bed processes under collinear wave and current flows from a two-phase sheet flow model
AU - Amoudry, Laurent O.
AU - Liu, Philip L.F.
N1 - Funding Information:
We wish to thank two anonymous reviewers for their comments, which greatly helped to improve the manuscript. L.O. Amoudry wishes to acknowledge the support of the Natural Environment Research Council (NERC), through core funding to the Proudman Oceanographic Laboratory (now National Oceanography Centre). P. L.-F. Liu would like to acknowledge the support from National Science Foundation, New York Sea Grant Institute through research grants to Cornell University. He would also like to thank the Humboldt Foundation for the Research Award Fellowship.
PY - 2010/7
Y1 - 2010/7
N2 - Sediment transport models require appropriate representation of near-bed processes. We aim here to explore the parameterizations of bed shear stress, bed load transport rate and near-bed sediment erosion rate under the sheet flow regime. To that end, we employ a one-dimensional two-phase sheet flow model which is able to resolve the intrawave boundary layer and sediment dynamics at a length scale on the order of the sediment grain. We have conducted 79 numerical simulations to cover a range of collinear wave and current conditions and sediment diameters in the range 210-460. γm. The numerical results confirm that the intrawave bed shear stress leads the free stream velocity, and we assess an explicit expression relating the phase lead to the maximum velocity, wave period and bed roughness. The numerical sheet flow model is also used to provide estimates for the bed load transport rate and to inspect the near-bed sediment erosion. A common bed load transport rate formulation and two typical reference concentration approaches are assessed. A dependence of the bed load transport rate on the sediment grain diameter is observed and parameterized. Finally, the intrawave near-bed vertical sediment flux is further investigated and related to the time derivative of the bed shear stress.
AB - Sediment transport models require appropriate representation of near-bed processes. We aim here to explore the parameterizations of bed shear stress, bed load transport rate and near-bed sediment erosion rate under the sheet flow regime. To that end, we employ a one-dimensional two-phase sheet flow model which is able to resolve the intrawave boundary layer and sediment dynamics at a length scale on the order of the sediment grain. We have conducted 79 numerical simulations to cover a range of collinear wave and current conditions and sediment diameters in the range 210-460. γm. The numerical results confirm that the intrawave bed shear stress leads the free stream velocity, and we assess an explicit expression relating the phase lead to the maximum velocity, wave period and bed roughness. The numerical sheet flow model is also used to provide estimates for the bed load transport rate and to inspect the near-bed sediment erosion. A common bed load transport rate formulation and two typical reference concentration approaches are assessed. A dependence of the bed load transport rate on the sediment grain diameter is observed and parameterized. Finally, the intrawave near-bed vertical sediment flux is further investigated and related to the time derivative of the bed shear stress.
UR - http://www.scopus.com/inward/record.url?scp=77954622669&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77954622669&partnerID=8YFLogxK
U2 - 10.1016/j.csr.2010.04.009
DO - 10.1016/j.csr.2010.04.009
M3 - Article
AN - SCOPUS:77954622669
SN - 0278-4343
VL - 30
SP - 1403
EP - 1416
JO - Continental Shelf Research
JF - Continental Shelf Research
IS - 13
ER -