Permeability (materials science): Difference between revisions

Permeability is a property of porous materials that is an indication of the ability for fluids (gas or liquid) to flow through them. Fluids can more easily flow through a material with high permeability than one with low permeability.<ref>{{Cite web|title=Reading: Porosity and Permeability {{!}} Geology|url=https://courses.lumenlearning.com/geo/chapter/reading-porosity-and-permeability/|access-date=2022-01-14|website=courses.lumenlearning.com}}</ref> The permeability of a medium is related to the [[porosity]], but also to the shapes of the pores in the medium and their level of connectedness.<ref>{{cite journal |last1=Fu |first1=Jinlong |last2=Thomas |first2=Hywel R. |last3=Li |first3=Chenfeng |title=Tortuosity of porous media: Image analysis and physical simulation |journal=Earth-Science Reviews |date=January 2021 |volume=212 |pages=103439 |doi=10.1016/j.earscirev.2020.103439|bibcode=2021ESRv..21203439F |s2cid=229386129 |url=https://cronfa.swan.ac.uk/Record/cronfa55808/Download/55808__18817__4aeefe32b0ee4ae7993bff0531362902.pdf }}</ref> Fluid flows can also be influenced in different [[Lithology|lithological settings]] by brittle deformation of rocks in [[Fault (geology)|fault zones]]; the mechanisms by which this occurs are the subject of [[fault zone hydrogeology]].<ref name="faultzone">{{Cite journal|last1=Bense|first1=V.F.|last2=Gleeson|first2=T.|last3=Loveless|first3=S.E.|last4=Bour|first4=O.|last5=Scibek|first5=J.|date=2013|title=Fault zone hydrogeology|url=https://linkinghub.elsevier.com/retrieve/pii/S0012825213001657|journal=Earth-Science Reviews|language=en|volume=127|pages=171–192|bibcode=2013ESRv..127..171B|doi=10.1016/j.earscirev.2013.09.008}}</ref> Permeability is also affected by the pressure inside a material.

Tissue such as brain, liver, muscle, etc can be treated as a heterogeneous porous medium. Describing the flow of biofluids (blood, cerebrospinal fluid, etc.) within such a medium requires a full 3-dimensional [[Anisotropy|anisotropic]] treatment of the tissue. In this case the [[Scalar (physics)|scalar]] hydraulic permeability is replaced with the hydraulic permeability [[tensor]] so that Darcy's Law reads<ref>{{Cite journal|last=Sowinski|first=Damian|title=Poroelasticity as a Model of Soft Tissue Structure: Hydraulic Permeability Reconstruction for Magnetic Resonance Elastography in Silico|journal=Frontiers in Physics|year=2021|volume=8|page=637|arxiv=2012.03993|doi=10.3389/fphy.2020.617582|pmid=36340954 |pmc=9635531 |bibcode=2021FrP.....8..637S|doi-access=free}}</ref>