An identification technique for evaluation of phenomenological coefficients in coupled flow in unsaturated soils

✍ Scribed by Raymond N. Yong; Da-Ming Xu

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 762 KB
• Volume: 12
• Category: Article
• ISSN: 0363-9061
• DOI: 10.1002/nag.1610120304

✦ Synopsis

To determine moisture movement and heat transfer through an unsaturated soil under temperature and volumetric water content gradients, it is necessary to have knowledge of phenomenological coefficients of the soil. However, in unsaturated flow, i.e. flow through unsaturated soil, these phenomenological coefficients are not constants, but vary with volumetric water content as well as temperature. In this paper, an identification technique is proposed for evaluation of the phenomenological coefficients. The phenomenological coefficients are first assumed to be certain kinds of functions of volumetric water content and temperature. The choice of the functional forms is based on an understanding of the physical situation, and previous knowledge of water flow in the isothermal case. The constant parameters associated with the functional forms are evaluated through the use of the identification technique. Once these phenomenological coefficients are obtained as certain functions of the volumetric water content and the temperature for a specified soil, analysis of coupled moisture flow and heat transfer in the unsaturated soil can proceed.