Macroscopic equations for vapor transport in a multi-layered unsaturated zone
نویسنده
چکیده
Using the method of homogenization, we present a systematic derivation of the macroscopic equations for air ̄ow and chemical vapor transport in an unsaturated zone with a periodic structure of heterogeneity. The eective speci®c discharge and hydrodynamic dispersion coecient are expressible in terms of some cell functions, whose analytical solutions are sought for the simple case of alternate stacking of two strictly plane layers of dierent properties. For this kind of bi-layered composite, the eects of convection velocity and layer property contrasts on the longitudinal and transverse components of the hydrodynamic dispersion coecient are investigated. Ó 1999 Elsevier Science Limited. All rights reserved
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