Author(s): A. W. Bruens; J. Pietrzak; J. C. Winterwerp

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Keywords: Turbulence decay; Density stratification; Entrainment; Cohesivesediments; Concentrated benthic suspension

Abstract: This paper deals with experiments on the decay of non-locally produced turbulence over a pool filled with a dense fluid. Upstream of the depression, turbulence is produced mainly as a result of bed friction. In the depression friction and the production of turbulence is for the larger part suppressed and the non-locally produced turbulence is advected over the dense fluid and gradually decays in downstream direction. The scaling laws which have to be taken into account when interpreting the laboratory experiment with respect to field conditions are discussed in this paper. During the experiments, mean velocities as well as turbulent fluctuations are measured at several positions over the depression. The obtained data indicate a decrease of turbulence in downstream direction over the pool. While decaying though, this non-locally produced turbulence might entrain material from the dense fluid. The entrainment rates are also measured. The results indicate a decrease in downstream direction, as the local Richardson number decreases in this direction.

DOI:

Year: 2001