Author(s): Ladislav Roušar; Zbyněk Zachoval; Pierre Julien

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Keywords: Incipient motion; mathematical model; relative submergence; sediment transport; Shields parameter

Abstract: The influence of several parameters on the incipient motion of gravels has been carefully examined from theoretical and experimental standpoints. The effect of the longitudinal bed slope is significant and well described with existing methods. This analysis shows that the effects of the grain Reynolds number and relative submergence are negligible for turbulent flows over hydraulically rough boundaries. Laboratory experiments for homogeneous gravels on a plane bed provided detailed measurements of both mean flow velocity and velocity fluctuations for the analysis of the lift and drag coefficients. This analysis of the lift and drag coefficients enables a better evaluation of the Shields parameter for incipient motion as a function of the angle of repose . The theoretical developments presented in this paper are corroborated by the results of our laboratory experiments as well as many others available in the literature.

DOI: https://doi.org/10.1080/00221686.2016.1212286

Year: 2016