Fluid Permeability

on . Posted in Geotechnical Engineering

Fluid permeability is the ability of a fluid (liquids or gases) to pass through a porous medium, such as soil, rock, or a membrane.  It is a measure of how easily a fluid can flow through the medium.  The term fluid permeability doesn't refer to a specific type of fluid but rather describes the property of a fluid in its interaction with a porous medium.  In the context of fluid dynamics and porous media, the term is commonly used to describe the flow of liquids or gases through materials with interconnected pore spaces.  This property is essential in various fields such as geology, hydrology, petroleum engineering, chemical engineering, and environmental science.

For example, in geology and hydrology, fluid permeability determines the movement of groundwater through soil or rock formations.  In petroleum engineering, it governs the flow of oil, gas, and water through reservoir rocks.  In chemical engineering, it is crucial for processes involving filtration, membrane separation, and fluid transport through porous materials.

Fluid permeability is influenced by factors such as the size, shape, and distribution of pores in the medium, as well as the viscosity and pressure of the fluid.  Materials with high permeability allow fluids to flow through more easily, while those with low permeability restrict fluid flow.


Fluid Permeability FORMULA

\( k = v \; ( \mu \; \Delta x \;/\; \Delta p )  \)     (Fluid Permeability)

\( v =  k \; \Delta p \;/\; \mu \; \Delta x   \)

\( \mu =  k \; \Delta p \;/\; v \; \Delta x   \)

\( \Delta x =  k \; \Delta p \;/\; v \; \mu   \)

\( \Delta p =  ( \mu \; \Delta x \;/\; k ) \; v  \)

Symbol English Metric
\( k \)  (Greek symbol mu) = permeability of a medium \(ft^2\) \(m^2\)
\( v \) = fluid velocity through porous media \(ft\;/\;sec\) \(m\;/\;s\)  
\( \mu \)  (Greek symbol mu) = dynamic viscosity of the fluid \(lbf-sec\;/\;ft^2\) \(Pa-s \)
\( \Delta x \) = thickness of the bed of the porous medium \(ft\) \(m\)
\( \Delta p \) = applied pressure difference \(lbf \;/\; in^2\) \(Pa\)


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Tags: Fluid Soil