Effects of capillary heterogeneity on vapor—liquid counterflow in porous media

✍ Scribed by A.K. Stubos; C. Satik; Y.C. Yortsos

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 886 KB
• Volume: 36
• Category: Article
• ISSN: 0017-9310
• DOI: 10.1016/s0017-9310(05)80281-9

✦ Synopsis

Based on a continuum description, the effect of capillary heterogeneity, induced by variation in permeability, on the steady state, countercurrent, vapor liquid flow in porous media is analyzed. It is shown that the heterogeneity acts as a body force, that may enhance or diminish gravity effects on heat pipes. Selection rules that determine the steady states reached in homogeneous, gravity-driven heat pipes are also formulated. It is shown that the "infinite' two-phase zone may terminate by a substantial change in the permeability somewhere in the medium. The two possible sequences, liquid liquid dominated~lry, or liquid vapor dominated~:lry find applications in geothermal systems. Finally. it is shown that although weak heterogeneity affects only gravity controlled flows, stronger variations in permeability can give rise to significant capillary effects.