A SPH elastic-viscoplastic model for granular flows and bed-load transport. (January 2018)

• Record Type: Journal Article
• Authors: Ghaïtanellis, Alex; Violeau, Damien; Ferrand, Martin; Abderrezzak, Kamal El Kadi; Leroy, Agnès; Joly, Antoine
• Is Part Of: Advances in water resources. Volume 111(2018)
• Page Start: 156
• Page End: 173
• Publication Date: 2018-01
• Subjects: Smoothed particle hydrodynamics -- Sediment transport -- Granular rheology -- Viscoplastic materials; Hydrology -- Periodicals; Hydrodynamics -- Periodicals; Hydraulic engineering -- Periodicals; 551.48
• DOI: 10.1016/j.advwatres.2017.11.007
• Languages: English
• ISSNs: 0309-1708

Abstract

Highlights: A novel multi-fluid model is proposed in WCSPH with semi-analytical boundary conditions. An elastic-viscoplastic model is used and improved to model granular flows and bed-load transport. The model is based on the granular properties of the material and is free of numerical parameters. Experiments of granular soil collapse and bed-load transport experiments are well reproduced. Abstract: An elastic-viscoplastic model (Ulrich, 2013) is combined to a multi-phase SPH formulation (Hu and Adams, 2006; Ghaitanellis et al., 2015) to model granular flows and non-cohesive sediment transport. The soil is treated as a continuum exhibiting a viscoplastic behaviour. Thus, below a critical shear stress ( i.e. the yield stress), the soil is assumed to behave as an isotropic linear-elastic solid. When the yield stress is exceeded, the soil flows and behaves as a shear-thinning fluid. A liquid-solid transition threshold based on the granular material properties is proposed, so as to make the model free of numerical parameter. The yield stress is obtained from Drucker–Prager criterion that requires an accurate computation of the effective stress in the soil. A novel method is proposed to compute the effective stress in SPH, solving a Laplace equation. The model is applied to a two-dimensional soil collapse (Bui et al., 2008) and a dam break over mobile beds (Spinewine and Zech, 2007). Results are compared with experimental data and a good agreement is obtained.