Dense granular flow rheology in turbulent bedload transport - Archive ouverte HAL
Article Dans Une Revue Journal of Fluid Mechanics Année : 2016

Dense granular flow rheology in turbulent bedload transport

Résumé

The local granular rheology is investigated numerically in turbulent bedload transport. Considering spherical particles, steady uniform configurations are simulated using a coupled fluid-discrete-element model. The stress tensor is computed as a function of the depth for a series of simulations varying the Shields number, the specific density and the particle diameter. The results are analyzed in the framework of the µ(I) rheology and exhibit a collapse of both the shear to normal stress ratio and the solid volume fraction over a wide range of inertial numbers. Contrary to expectations, the effect of the interstitial fluid on the granular rheology is shown to be negligible, supporting recent work suggesting the absence of a clear transition between the free-fall and turbulent regime. In addition, data collapse is observed up to unexpectedly high inertial numbers I ∼ 2, challenging the existing conceptions and parametrization of the µ(I) rheology. Focusing upon bedload transport modelling, the results are pragmatically analyzed in the µ(I) framework in order to propose a granular rheology for bedload transport. The proposed rheology is tested using a 1D volume-averaged two-phase continuous model, and is shown to accurately reproduce the dense granular flow profiles and the sediment transport rate over a wide range of Shields numbers. The present contribution represents a step in the upscaling process from particle-scale simulations toward large-scale applications involving complex flow geometry.
Fichier principal
Vignette du fichier
MaurinEtAl_JFM2016.pdf (5.59 Mo) Télécharger le fichier
Origine Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-01399574 , version 1 (19-11-2016)

Identifiants

Citer

Raphaël Maurin, Julien Chauchat, Philippe Frey. Dense granular flow rheology in turbulent bedload transport. Journal of Fluid Mechanics, 2016, 804, pp.490 - 512. ⟨10.1017/jfm.2016.520⟩. ⟨hal-01399574⟩
93 Consultations
113 Téléchargements

Altmetric

Partager

More