Comment on the treatment of residual water content in “A consistent set of parametric models for the two-phase flow of immiscible fluids in the subsurface” by L. Luckner et al.

John R. Nimmo

doi:10.1029/91wr00165

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Comment on the treatment of residual water content in “A consistent set of parametric models for the two-phase flow of immiscible fluids in the subsurface” by L. Luckner et al.

John R. Nimmo

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Abstract

Luckner et al. [1989] (hereinafter LVN) present a clear summary and generalization of popular formulations used for convenient representation of porous media fluid flow characteristics, including water content ( θ ) related to suction ( h ) and hydraulic conductivity ( K ) related to θ or h. One essential but problematic element in the LVN models is the concept of residual water content ( θ r ; in LVN, θ w , r ). Most studies using θ r determine its value as a fitted parameter and make the assumption that liquid flow processes are negligible at θ values less than θ r . While the LVN paper contributes a valuable discussion of the nature of θ r , it leaves several problems unresolved, including fundamental difficulties in associating a definite physical condition with θ r , practical inadequacies of the models at low θ values, and difficulties in designating a main wetting curve.

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John R. Nimmo. 2008-01-08. Comment on the treatment of residual water content in “A consistent set of parametric models for the two-phase flow of immiscible fluids in the subsurface” by L. Luckner et al.. https://doi.org/10.1029/91wr00165

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