CaltechAUTHORS
  A Caltech Library Service

Continuum viscoplastic simulation of a granular column collapse on large slopes: μ(I) rheology and lateral wall effects

Martin, N. and Ionescu, I. R. and Mangeney, A. and Bouchut, F. and Farin, M. (2017) Continuum viscoplastic simulation of a granular column collapse on large slopes: μ(I) rheology and lateral wall effects. Physics of Fluids, 29 (1). Art. No. 013301. ISSN 1070-6631. http://resolver.caltech.edu/CaltechAUTHORS:20170119-132220916

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20170119-132220916

Abstract

We simulate here dry granular flows resulting from the collapse of granular columns on an inclined channel (up to 22°) and compare precisely the results with laboratory experiments. Incompressibility is assumed despite the dilatancy observed in the experiments (up to 10%). The 2-D model is based on the so-called μ(I) rheology that induces a Drucker-Prager yield stress and a variable viscosity. A nonlinear Coulomb friction term, representing the friction on the lateral walls of the channel, is added to the model. We demonstrate that this term is crucial to accurately reproduce granular collapses on slopes ≳10°, whereas it remains of little effect on the horizontal slope. Quantitative comparison between the experimental and numerical changes with time of the thickness profiles and front velocity makes it possible to strongly constrain the rheology. In particular, we show that the use of a variable or a constant viscosity does not change significantly the results provided that these viscosities are of the same order. However, only a fine tuning of the constant viscosity (η=1 Pa s) makes it possible to predict the slow propagation phase observed experimentally at large slopes. Finally, we observed that small-scale instabilities develop when refining the mesh (also called ill-posed behavior, characterized in the work of Barker et al. [“Well-posed and ill-posed behaviour of the μ(I)-rheology for granular flow,” J. Fluid Mech. 779, 794–818 (2015)] and in the present work) associated with the mechanical model. The velocity field becomes stratified and the bands of high velocity gradient appear. These model instabilities are not avoided by using variable viscosity models such as the μ(I) rheology. However we show that the velocity range, the static-flowing transition, and the thickness profiles are almost not affected by them.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1063/1.4971320DOIArticle
http://aip.scitation.org/doi/full/10.1063/1.4971320PublisherArticle
Additional Information:© 2017 AIP Publishing. Received 19 July 2016; accepted 18 November 2016; published online 12 January 2017. This work has been partially funded by the USPC project PAGES, CNCS-UEFISCDI Project No. PN-II-ID-PCE-2011-3-0045, and by the ERC Contract No. ERC-CG-2013-PE10-617472 SLIDEQUAKES.
Group:Seismological Laboratory
Funders:
Funding AgencyGrant Number
USPC project PAGESUNSPECIFIED
Consiliul National al Cercetarii Stiintifice (CNCS)PN-II-ID-PCE-2011-3-0045
European Research Council (ERC)ERC-CG-2013-PE10-617472 SLIDEQUAKES
Record Number:CaltechAUTHORS:20170119-132220916
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20170119-132220916
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:73555
Collection:CaltechAUTHORS
Deposited By: Ruth Sustaita
Deposited On:19 Jan 2017 23:25
Last Modified:19 Jan 2017 23:25

Repository Staff Only: item control page