000212526 001__ 212526
000212526 005__ 20190317000304.0
000212526 022__ $$a2169-9003
000212526 02470 $$2ISI$$a000357994400009
000212526 0247_ $$a10.1002/2014Jf003294$$2doi
000212526 037__ $$aARTICLE
000212526 245__ $$aGranulation of snow: From tumbler experiments to discrete element simulations
000212526 269__ $$a2015
000212526 260__ $$c2015
000212526 300__ $$a20
000212526 336__ $$aJournal Articles
000212526 520__ $$aIt is well known that snow avalanches exhibit granulation phenomena, i.e., the formation of large and apparently stable snow granules during the flow. The size distribution of the granules has an influence on flow behavior which, in turn, affects runout distances and avalanche velocities. The underlying mechanisms of granule formation are notoriously difficult to investigate within large-scale field experiments, due to limitations in the scope for measuring temperatures, velocities, and size distributions. To address this issue we present experiments with a concrete tumbler, which provide an appropriate means to investigate granule formation of snow. In a set of experiments at constant rotation velocity with varying temperatures and water content, we demonstrate that temperature has a major impact on the formation of granules. The experiments showed that granules only formed when the snow temperature exceeded -1(degrees)C. No evolution in the granule size was observed at colder temperatures. Depending on the conditions, different granulation regimes are obtained, which are qualitatively classified according to their persistence and size distribution. The potential of granulation of snow in a tumbler is further demonstrated by showing that generic features of the experiments can be reproduced by cohesive discrete element simulations. The proposed discrete element model mimics the competition between cohesive forces, which promote aggregation, and impact forces, which induce fragmentation, and supports the interpretation of the granule regime classification obtained from the tumbler experiments. Generalizations, implications for flow dynamics, and experimental and model limitations as well as suggestions for future work are discussed.
000212526 6531_ $$agranulation of snow
000212526 6531_ $$aavalanche
000212526 6531_ $$asnow temperature
000212526 6531_ $$acohesive granular material
000212526 700__ $$uWSL Inst Snow & Avalanche Res SLF, Davos, Switzerland$$aSteinkogler, Walter
000212526 700__ $$uWSL Inst Snow & Avalanche Res SLF, Davos, Switzerland$$g270291$$aGaume, Johan$$0250042
000212526 700__ $$uWSL Inst Snow & Avalanche Res SLF, Davos, Switzerland$$aLoewe, Henning
000212526 700__ $$uWSL Inst Snow & Avalanche Res SLF, Davos, Switzerland$$aSovilla, Betty
000212526 700__ $$uWSL Inst Snow & Avalanche Res SLF, Davos, Switzerland$$g167659$$aLehning, Michael$$0245914
000212526 773__ $$q1107-1126$$k6$$j120$$tJournal Of Geophysical Research-Earth Surface
000212526 8560_ $$fvalerie.charbonnier@epfl.ch
000212526 8564_ $$uhttps://infoscience.epfl.ch/record/212526/files/2014JF003294.pdf$$zFinal$$s57928717
000212526 909C0 $$xU12533$$0252326$$pCRYOS
000212526 909CO $$qGLOBAL_SET$$particle$$ooai:infoscience.tind.io:212526$$pENAC
000212526 917Z8 $$x219016
000212526 937__ $$aEPFL-ARTICLE-212526
000212526 973__ $$rREVIEWED$$sPUBLISHED$$aEPFL
000212526 980__ $$aARTICLE
000212526 999C0 $$mjohan.gaume@epfl.ch$$0264042$$zCharbonnier, Valérie$$xU13659$$pSLAB