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Thermomechanical Theory of Capillary Soil Water
Author(s) -
Prunty Lyle
Publication year - 2009
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2008.0119
Subject(s) - capillary action , reciprocity (cultural anthropology) , observable , porous medium , thermodynamics , capillary pressure , simple (philosophy) , liquid water , soil water , mechanics , chemistry , porosity , physics , environmental science , soil science , psychology , social psychology , philosophy , organic chemistry , epistemology , quantum mechanics
Thermomolecular pressure difference (TPD) and the mechanocaloric effect (MCE) are distinct, observable phenomena. Predictions of both arise in a general manner from linear irreversible thermodynamics. Analysis of water as a single mobile substance in capillary media independent of the usual irreversible thermodynamic concepts nevertheless has been shown to lead to the same results. Equations for water vapor, liquid water, and heat transport according to irreversible thermodynamic theory, including the Onsager reciprocity principle, are presented. Application of these equations to simple capillary geometries serves to illustrate the TPD and MCE effects. Results to be expected in degraded conditions (random porous media), relative to the structured capillary results are discussed. Before today, Onsager reciprocity is not generally enforced in models of simultaneous soil water and heat transport. At the same time, however, current models are reputedly inadequate or at least in need of refinement.