Comments on avalanche flow models based on the concept of random kinetic energy
In a series of papers, Bartelt and co-workers developed novel snow-avalanche models in which random kinetic energy 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 RK-dependent friction parameters. This w...
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ftngicom:oai:brage.bibsys.no:11250/2484378 2023-05-15T16:57:09+02:00 Comments on avalanche flow models based on the concept of random kinetic energy Issler, Dieter Jenkins, JT McElwaine, J.N. 2018-02-13T12:22:38Z http://hdl.handle.net/11250/2484378 eng eng Journal of Glaciology. 2017, . urn:issn:0022-1430 http://hdl.handle.net/11250/2484378 cristin:1504015 16 Journal of Glaciology Peer reviewed Journal article 2018 ftngicom 2018-09-20T09:19:49Z In a series of papers, Bartelt and co-workers developed novel snow-avalanche models in which random kinetic energy 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 RK-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 is 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. publishedVersion Article in Journal/Newspaper Journal of Glaciology Unknown |
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description |
In a series of papers, Bartelt and co-workers developed novel snow-avalanche models in which random kinetic energy 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 RK-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 is 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. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Issler, Dieter Jenkins, JT McElwaine, J.N. |
spellingShingle |
Issler, Dieter Jenkins, JT McElwaine, J.N. Comments on avalanche flow models based on the concept of random kinetic energy |
author_facet |
Issler, Dieter Jenkins, JT McElwaine, J.N. |
author_sort |
Issler, Dieter |
title |
Comments on avalanche flow models based on the concept of random kinetic energy |
title_short |
Comments on avalanche flow models based on the concept of random kinetic energy |
title_full |
Comments on avalanche flow models based on the concept of random kinetic energy |
title_fullStr |
Comments on avalanche flow models based on the concept of random kinetic energy |
title_full_unstemmed |
Comments on avalanche flow models based on the concept of random kinetic energy |
title_sort |
comments on avalanche flow models based on the concept of random kinetic energy |
publishDate |
2018 |
url |
http://hdl.handle.net/11250/2484378 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
16 Journal of Glaciology |
op_relation |
Journal of Glaciology. 2017, . urn:issn:0022-1430 http://hdl.handle.net/11250/2484378 cristin:1504015 |
_version_ |
1766048429229735936 |