Visco-plastic models of isothermal lava domes

The dynamics of expanding domes of isothermal lava are studied by treating the lava as a viscoplastic material with the Herschel–Bulkley constitutive law. Thin-layer theory is developed for radially symmetric extrusions onto horizontal plates. This provides an evolution equation for the thickness of the fluid that can be used to model expanding isothermal lava domes. Numerical and analytical solutions are derived that explore the effects of yield stress, shear thinning and basal sliding on the dome evolution. The results are briefly compared with an experimental study. It is found that it is difficult to unravel the combined effects of shear thinning and yield stress; this may prove important to studies that attempt to infer yield stress from morphology of flowing lava.

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Combined effects of fluid shear-thinning and yield stress on heat transfer from an isothermal spheroid

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2015.11.001 ◽

2016 ◽

Vol 93 ◽

pp. 803-826 ◽

Cited By ~ 4

Author(s):

Anoop K. Gupta ◽

R.P. Chhabra

Keyword(s):

Heat Transfer ◽

Yield Stress ◽

Shear Thinning ◽

Combined Effects ◽

Fluid Shear

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Coarse Particles in Homogeneous Non-Newtonian Slurries: Combined Effects of Shear-Thinning Viscosity and Fluid Yield Stress on Drag and Heat Transfer from Hemispherical Particles

Transactions of the Indian Institute of Metals ◽

10.1007/s12666-016-0983-8 ◽

2016 ◽

Vol 70 (2) ◽

pp. 341-358 ◽

Cited By ~ 1

Author(s):

Om Prakash ◽

S. A. Patel ◽

A. K. Gupta ◽

R. P. Chhabra

Keyword(s):

Heat Transfer ◽

Yield Stress ◽

Shear Thinning ◽

Combined Effects ◽

Coarse Particles

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An experimental study of the motion of ice past obstacles by the process of regelation

Journal of Glaciology ◽

10.1017/s0022143000030744 ◽

1976 ◽

Vol 17 (75) ◽

pp. 79-98 ◽

Cited By ~ 14

Author(s):

E. M. Morris

Keyword(s):

Thermal Conductivity ◽

Experimental Study ◽

Cross Sections ◽

Transition Point ◽

Water Layer ◽

Single Object ◽

Two Systems ◽

Basal Sliding

AbstractThe results of regelation experiments, in which a single object is pulled through ice, cannot be applied directly to the problem of basal sliding in glaciers because the two systems have different geometries. When the force applied to a single object is small, impurities trapped in the regelation water-layer around the object inhibit the regelation process. At larger forces, above the Drake-Shreve transition point, impurities are shed in a trace behind the object. However, when ice moves over a series of obstacles a trace may exist above and below the transition point. The regelation velocity below the transition point is not reduced by the effect of trapped impurities. In an experiment in which brass cylingerrs of various cross-sections rotate in ice, the ratio between the expected regelation velocity, calculated using the basal-sliding theory of Nye, and the measured regelation velocity is 8±2, both above and below the transition point. The same ratio has been obtained by other workers with wires of similar thermal conductivity above the transition point. Measurements of température differences indicate that supercooling cannot be the main source of the unexpectedly low regelation velocities above the transition point.

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