ABSTRACT
Results ............................................................................................. 316 11.3.5 Further Discussion of Capillary Wicking Results .................... 319
11.4 Summary ..................................................................................................... 320 Acknowledgments .............................................................................................. 320 Nomenclature ...................................................................................................... 320
Greek Letters ............................................................................................... 321 References ............................................................................................................. 322
In this chapter, we examine the phenomena of capillary wicking with a focus on mixture theory models of deformable porous materials. Wicking, or the imbibition of a liquid into a porous material through capillary suction, occurs in a wide variety of physical processes. These include familiar ones such as the clean up of liquid spills using paper towels or sponges and the design of fabrics ranging from yarn (Pezron et al. 1995; Monaenkova and Kornev 2010) to high-tech fabrics for the optimization of wicking and cooling/ drying properties in sports performance clothing (socks, shirts, caps, etc.). They also occur in environmental phenomena ranging from ˆows through sand or soils (e.g., Bear 1972) to the capillary rise of water into snow (Coléou et al. 1999; Jordan et al. 1999) and industrial processes such as coating and imbibition of iron ore pellets to optimize their performance (Pavlovets 2010). These examples include scenarios where the penetration of the ˆuid into a porous material is accompanied by the deformation of the porous material. A fascinating historical perspective on the foundations of porous media, including mixture theory and early competing ideas on the description of deformable porous solids, is given in the book by de Boer (2000).
