Comments on avalanche flow models based on the concept of random kinetic energy

Issler, Dieter; Jenkins, James T.; McElwaine, Jim N.

doi:10.1017/jog.2017.62

Comments on avalanche flow models based on the concept of random kinetic energy

Issler, Dieter; Jenkins, James T.; McElwaine, Jim N.

Authors

Dieter Issler

James T. Jenkins

Professor Jim Mcelwaine james.mcelwaine@durham.ac.uk
Professor

Abstract

In a series of papers, Bartelt and co-workers developed novel snow-avalanche models in which random kinetic energy (RKE) RK (a.k.a. granular temperature) is a key concept. The earliest models were for a single, constant density layer, using a Voellmy model but with R K -dependent friction parameters. This was then extended to variable density, and finally a suspension layer (powder-snow cloud) was added. The physical basis and mathematical formulation of these models are critically reviewed here, with the following main findings: (i) Key assumptions in the original RKE model differ substantially from established results on dense granular flows; in particular, the effective friction coefficient decreases to zero with velocity in the RKE model. (ii) In the variable-density model, non-canonical interpretation of the energy balance leads to a third-order evolution equation for the flow depth or density, whereas the stated assumptions imply a first-order equation. (iii) The model for the suspension layer neglects gravity and disregards well-established theoretical and experimental results on particulate gravity currents. Some options for improving these aspects are discussed.

Citation

Issler, D., Jenkins, J. T., & McElwaine, J. N. (2018). Comments on avalanche flow models based on the concept of random kinetic energy. Journal of Glaciology, 64(243), 148-164. https://doi.org/10.1017/jog.2017.62

Journal Article Type	Article
Acceptance Date	Sep 13, 2017
Online Publication Date	Nov 27, 2017
Publication Date	Feb 1, 2018
Deposit Date	Sep 27, 2017
Publicly Available Date	Sep 28, 2017
Journal	Journal of Glaciology
Print ISSN	0022-1430
Electronic ISSN	1727-5652
Publisher	International Glaciological Society
Peer Reviewed	Peer Reviewed
Volume	64
Issue	243
Pages	148-164
DOI	https://doi.org/10.1017/jog.2017.62

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Copyright Statement
© The Author(s) 2017 This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.