Shear-enhanced convection in a mushy layer
We investigate the effect of an external shear flow on the buoyant instabilities inherent in the directional solidification of a dendritic mushy layer. In the presence of an external shear flow, perturbations of the mush–liquid interface lead to perturbed flow in the bulk fluid that create pressure...
Published in: | Journal of Fluid Mechanics |
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Language: | English |
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Cambridge University Press (CUP)
2008
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Online Access: | http://dx.doi.org/10.1017/s0022112008002991 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112008002991 |
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crcambridgeupr:10.1017/s0022112008002991 2024-03-03T08:48:45+00:00 Shear-enhanced convection in a mushy layer NEUFELD, JEROME A. WETTLAUFER, J. S. 2008 http://dx.doi.org/10.1017/s0022112008002991 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112008002991 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Journal of Fluid Mechanics volume 612, page 339-361 ISSN 0022-1120 1469-7645 Mechanical Engineering Mechanics of Materials Condensed Matter Physics journal-article 2008 crcambridgeupr https://doi.org/10.1017/s0022112008002991 2024-02-08T08:40:49Z We investigate the effect of an external shear flow on the buoyant instabilities inherent in the directional solidification of a dendritic mushy layer. In the presence of an external shear flow, perturbations of the mush–liquid interface lead to perturbed flow in the bulk fluid that create pressure variations along the mush–liquid interface. These pressure variations drive flow in the mushy layer. A numerical analysis of the stability of the system provides the critical porous-medium Rayleigh number as a function of both the external flow speed and the wavenumber of the interfacial perturbations. In the limit of zero external flow we recover the so-called boundary and mushy layer modes of buoyancy-driven convection first established by Worster ( J. Fluid Mech ., vol. 237, 1992 b , p. 649). We find that the application of an external flow can significantly reduce the stability of both the boundary and mushy layer modes. The resultant forced mushy layer mode gives rise to the formation of channels of reduced solid fraction perpendicular to the applied flow that are distinct from the planform found in the absence of an external flow. The stability of the system is examined as a function of the principal thermodynamic and dynamic parameters, and the results are applied to the solidification of sea ice in the presence of vigorous oceanic flow. Article in Journal/Newspaper Sea ice Cambridge University Press Journal of Fluid Mechanics 612 339 361 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Mechanical Engineering Mechanics of Materials Condensed Matter Physics |
spellingShingle |
Mechanical Engineering Mechanics of Materials Condensed Matter Physics NEUFELD, JEROME A. WETTLAUFER, J. S. Shear-enhanced convection in a mushy layer |
topic_facet |
Mechanical Engineering Mechanics of Materials Condensed Matter Physics |
description |
We investigate the effect of an external shear flow on the buoyant instabilities inherent in the directional solidification of a dendritic mushy layer. In the presence of an external shear flow, perturbations of the mush–liquid interface lead to perturbed flow in the bulk fluid that create pressure variations along the mush–liquid interface. These pressure variations drive flow in the mushy layer. A numerical analysis of the stability of the system provides the critical porous-medium Rayleigh number as a function of both the external flow speed and the wavenumber of the interfacial perturbations. In the limit of zero external flow we recover the so-called boundary and mushy layer modes of buoyancy-driven convection first established by Worster ( J. Fluid Mech ., vol. 237, 1992 b , p. 649). We find that the application of an external flow can significantly reduce the stability of both the boundary and mushy layer modes. The resultant forced mushy layer mode gives rise to the formation of channels of reduced solid fraction perpendicular to the applied flow that are distinct from the planform found in the absence of an external flow. The stability of the system is examined as a function of the principal thermodynamic and dynamic parameters, and the results are applied to the solidification of sea ice in the presence of vigorous oceanic flow. |
format |
Article in Journal/Newspaper |
author |
NEUFELD, JEROME A. WETTLAUFER, J. S. |
author_facet |
NEUFELD, JEROME A. WETTLAUFER, J. S. |
author_sort |
NEUFELD, JEROME A. |
title |
Shear-enhanced convection in a mushy layer |
title_short |
Shear-enhanced convection in a mushy layer |
title_full |
Shear-enhanced convection in a mushy layer |
title_fullStr |
Shear-enhanced convection in a mushy layer |
title_full_unstemmed |
Shear-enhanced convection in a mushy layer |
title_sort |
shear-enhanced convection in a mushy layer |
publisher |
Cambridge University Press (CUP) |
publishDate |
2008 |
url |
http://dx.doi.org/10.1017/s0022112008002991 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112008002991 |
genre |
Sea ice |
genre_facet |
Sea ice |
op_source |
Journal of Fluid Mechanics volume 612, page 339-361 ISSN 0022-1120 1469-7645 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0022112008002991 |
container_title |
Journal of Fluid Mechanics |
container_volume |
612 |
container_start_page |
339 |
op_container_end_page |
361 |
_version_ |
1792505750655860736 |