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Influence of turbulence on bed load sediment transport
journal contribution
posted on 2003-01-01, 00:00 authored by B Sumer, Lloyd ChuaLloyd Chua, N Cheng, J FredsoeThis paper summarizes the results of an experimental study on the influence of an external turbulence field on the bed load sediment transport in an open channel. The external turbulence was generated by (1) a horizontal pipe placed halfway through the depth h; (2) a series of grids with a clearance of about one-third of the depth from the bed, and extending over a finite length of the flume; and (3) a series of grids with a clearance in the range (0.1−1.0)h from the bed, but extending over the entire length of the flume. Two kinds of experiments were conducted: plane-bed experiments and ripple-covered-bed experiments. In the former case, the flow in the presence of the turbulence generator was adjusted so that the mean bed shear stress was the same as in the case without the turbulence generator in order to single out the effect of the external turbulence on the sediment transport. In the ripple-covered-bed case, the mean and turbulence quantities of the streamwise component of the velocity were measured, and the Shields parameter, due to skin friction, was determined. The Shields parameter, together with the RMS value of the streamwise velocity fluctuations, was correlated with the sediment transport rate. The sediment transport increases markedly with increasing turbulence level.
History
Journal
Journal of hydrologic engineeringVolume
129Issue
8Pagination
585 - 596Publisher
American Society of Civil EngineersLocation
Reston, Va.ISSN
1943-7900Language
engPublication classification
C1.1 Refereed article in a scholarly journalCopyright notice
2003, American Society of Civil EngineersUsage metrics
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