Author(s): M. Grunzner; P. Rutschmann
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Keywords: No Keywords
Abstract: Based on Shields experiments Fenton and Abbott (1977) have shown the effect of exposure on the beginning of bedload transport of cohesionless grains. They glued grains on a laboratory flume bed and protruded one single grain with a stamp into the flow measuring the offset for initial motion of the grain by the flow. The present paper shows the potential of an up-to-date numerical approach with respect to these experiments. Due to difficulties with the geometric module, that identifies particle collisions and particles actually melt together slightly, the present paper mainly deals with the hydrodynamics of the 1977 experiments and shows one single, qualitative test with initial motion of an exposed grain. One major difficulty in reproducing the experiments lay in the fact that the experiments were conducted and described using time and cross-sectionally averaged hydraulic parameters. A highly sophisticated turbulent 3D CFD model has a much finer resolution both in space and time and thus a comparison of the two concepts is not trivial.
Year: 2009