Scaling for lobe and cleft patterns in particle-laden gravity currents
Lobe and cleft patterns are frequently observed at the leading edge of gravity currents, including non-Boussinesq particle-laden currents such as powder snow avalanches. Despite the importance of the instability in driving air entrainment, little is known about its origin or the mechanisms behind it...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2013-02-01
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| Series: | Nonlinear Processes in Geophysics |
| Online Access: | http://www.nonlin-processes-geophys.net/20/121/2013/npg-20-121-2013.pdf |
| _version_ | 1811215789455310848 |
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| author | A. Jackson B. Turnbull R. Munro |
| author_facet | A. Jackson B. Turnbull R. Munro |
| author_sort | A. Jackson |
| collection | DOAJ |
| description | Lobe and cleft patterns are frequently observed at the leading edge of gravity currents, including non-Boussinesq particle-laden currents such as powder snow avalanches. Despite the importance of the instability in driving air entrainment, little is known about its origin or the mechanisms behind its development. In this paper we seek to gain a better understanding of these mechanisms from a laboratory scale model of powder snow avalanches using lightweight granular material. <br><br> The instability mechanisms in these flows appear to be a combination of those found in both homogeneous Boussinesq gravity currents and unsuspended granular flows, with the size of the granular particles playing a central role in determining the wavelength of the lobe and cleft pattern. When scaled by particle diameter a relationship between the Froude number and the wavelength of the lobe and cleft pattern is found, where the wavelength increases monotonically with the Froude number. |
| first_indexed | 2024-04-12T06:29:34Z |
| format | Article |
| id | doaj.art-a80ecc36dbb44356a2f3a2b9f7719b13 |
| institution | Directory Open Access Journal |
| issn | 1023-5809 1607-7946 |
| language | English |
| last_indexed | 2024-04-12T06:29:34Z |
| publishDate | 2013-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Nonlinear Processes in Geophysics |
| spelling | doaj.art-a80ecc36dbb44356a2f3a2b9f7719b132022-12-22T03:44:04ZengCopernicus PublicationsNonlinear Processes in Geophysics1023-58091607-79462013-02-0120112113010.5194/npg-20-121-2013Scaling for lobe and cleft patterns in particle-laden gravity currentsA. JacksonB. TurnbullR. MunroLobe and cleft patterns are frequently observed at the leading edge of gravity currents, including non-Boussinesq particle-laden currents such as powder snow avalanches. Despite the importance of the instability in driving air entrainment, little is known about its origin or the mechanisms behind its development. In this paper we seek to gain a better understanding of these mechanisms from a laboratory scale model of powder snow avalanches using lightweight granular material. <br><br> The instability mechanisms in these flows appear to be a combination of those found in both homogeneous Boussinesq gravity currents and unsuspended granular flows, with the size of the granular particles playing a central role in determining the wavelength of the lobe and cleft pattern. When scaled by particle diameter a relationship between the Froude number and the wavelength of the lobe and cleft pattern is found, where the wavelength increases monotonically with the Froude number.http://www.nonlin-processes-geophys.net/20/121/2013/npg-20-121-2013.pdf |
| spellingShingle | A. Jackson B. Turnbull R. Munro Scaling for lobe and cleft patterns in particle-laden gravity currents Nonlinear Processes in Geophysics |
| title | Scaling for lobe and cleft patterns in particle-laden gravity currents |
| title_full | Scaling for lobe and cleft patterns in particle-laden gravity currents |
| title_fullStr | Scaling for lobe and cleft patterns in particle-laden gravity currents |
| title_full_unstemmed | Scaling for lobe and cleft patterns in particle-laden gravity currents |
| title_short | Scaling for lobe and cleft patterns in particle-laden gravity currents |
| title_sort | scaling for lobe and cleft patterns in particle laden gravity currents |
| url | http://www.nonlin-processes-geophys.net/20/121/2013/npg-20-121-2013.pdf |
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