PARADOXES AND REALITIES IN UNSATURATED FLOW THEORY
PARADOXES AND REALITIES IN UNSATURATED FLOW THEORY
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DOI：
10.1029/91wr01259
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发表时间：
1991-08-01
影响因子：
5.4
通讯作者：
HASSANIZADEH, SM
中科院分区：
文献类型：
--
作者：
GRAY, WG;HASSANIZADEH, SM
在当前应用的不饱和流动理论中，关于水相的状态方程、负绝对压力下的水相的概念、平衡时的静水压力梯度的适用性以及在问题表述中缺乏明确包含界面效应等方面存在悖论。 这里提出的不饱和流动理论消除了这些悖论，并表明毛细管压力和相对渗透率的滞后可以通过允许这些量取决于界面面积和饱和度来解释。 润湿势被证明是一个热力学函数，对于描述不饱和流动过程很重要。 气相和水相界面的动量平衡方程也有助于形成一组系统且易于处理的描述非饱和流动的方程。
In currently applied theory of unsaturated flow, paradoxes exist concerning the equation of state for the water phase, the idea of a water phase at negative absolute pressure, the applicability of the hydrostatic pressure gradient at equilibrium, and the lack of explicit inclusion of interface effects in the problem formulation. The theory of unsaturated flow presented here eliminates those paradoxes and indicates that the hysteresis in capillary pressure and relative permeability may be accounted for by allowing these quantities to depend on interfacial area as well as saturation. The wettability potential is shown to be a thermodynamic function which is important in describing unsaturated flow processes. The momentum balance equation for the interface between the air and water phases also contributes to a systematic and tractable set of equations which describe unsaturated flow.