Investigation of vertical size segregation in bedload sediment transport with a coupled fluid-discrete element model
1 Université Grenoble Alpes, Irstea, UR ETNA, 2 rue de la Papeterie-BP 76, F-38402 St-Martin-d’Hères, France
2 Université de Toulouse, INPT, UPS, Institut de Mécanique des Fluides de Toulouse, Allée Camille Soula, 31400 Toulouse, France
3 Univ. Grenoble Alpes, LEGI, G-INP, CNRS, F-38000 Grenoble, France
* Corresponding author: email@example.com
Published online: 30 June 2017
In order to gain understanding of kinetic sieving-type segregation in bedload sediment transport, numerical experiments of two-size particle mixtures were carried out, using a validated coupled fluid-discrete element model developed at Irstea. A 3D 10% steep domain consisting at initial time of a given number of layers of 4 mm particles deposited on top of a coarser 6 mm particle bed, was submitted to a turbulent and supercritical fluid shear flow (Shields numbers of 0.1 and 0.3). The elevation of the centre of mass of the infiltrated fine particles is observed to follow the same logarithmic decrease with time, whatever the initial number of fine layers. This decrease is steeper for a higher Shields number. The main result is that this typical behaviour is related at first order to the shear rate depth profile.
© The Authors, published by EDP Sciences, 2017
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