Item: Pore-Space Characterization of Wet Snow in the Pendular Regime
Title: Pore-Space Characterization of Wet Snow in the Pendular Regime
Proceedings: Proceedings of the 1996 International Snow Science Workshop, Banff, Canada
- Jim Frankenfield [ Cyberspace Snow and Avalanche Center ]
Abstract: Th geometry of wetting fluid pendular rings in a porous media can be used to characterize the media in this saturation on regime. A number of expressions for the volume and surface area of pendular rings in an ideal soil have been published but are not in agreement. A correct set of equations has been derived for an ideal soil of spheres and also for a sintered media represented by allowing the spheres to overlap. These volume and area expressions allow for the possibility of a non-zero contact angle between the wetting fluid and the solid. The transition between the pendular and funicular regimes occurs when either the pendular rings merge or the capillary pressure (Pc) across the wetting/non-wetting interface becomes zero. Use of the Laplace Equation and the ring geometry leads to an implicit equation for the Pc=O point. The roots of this equation are in general agreement with measured values of the transition saturation.Characteristic curves of Pc vs. Saturation can be generated as well. The basis for this is the thermodynamic relation P=dE/dV. Energy can be calculated by using the interfacial area expressions and the related surface energies. Young's equation and symmetry can be used to reduce the necessary surface energies to only the wetting/non-wetting surface tension. A spreadsheet can then be used to generate the characteristic curves.
Language of Article: English
Keywords: pendular rings, snow wetness
Digital Abstract Not Available