Style, R. W. and Peppin, S. S. L. (2011) The kinetics of icelens growth in porous media. Journal of Fluid Mechanics . (Submitted)

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Abstract
We analyse the growth rate of segregated ice (ice lenses) in freezing porous media. For typical colloidal materials such as soils we show that the commonlyemployed Clapeyron equation is not valid macroscopically at the interface between the ice lens and the surrounding porous medium owing to the viscous dynamics of flow in premelted films. This gives rise to an ‘interfacial resistance’ to flow towards the growing ice which causes a significant drop in predicted icegrowth (heave) rates and explains why many previous models predict icegrowth rates that are much larger than those seen in experiments. We derive an explicit formula for the icegrowth rate in a given porous medium, and show that this only depends on temperature and on the external pressures imposed on the freezing system. This growthrate formula contains a materialspecific function which can be calculated (with a knowledge of the of the geometry and material of the porous medium), but which is also readily experimentallymeasurable. We apply the formula to platelike particles, and obtain good agreement with previous experimental data. Finally we show how the interfacial resistance explains the observation that the maximum heave rate in soils occurs in mediumgrained particles such as silts, while heave rates are smaller for fine and coarse grained particles.
Item Type:  Article 

Subjects:  D  G > General 
Research Groups:  Oxford Centre for Collaborative Applied Mathematics 
ID Code:  1435 
Deposited By:  Peter Hudston 
Deposited On:  15 Nov 2011 08:36 
Last Modified:  29 May 2015 19:08 
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