Dictionary:Darcy’s law

A relationship for 1D fluid flow rate q:

$q=({\frac {kA}{\mu }}){\frac {\Delta p}{\Delta x}}$ ,

where k=permeability, A=cross-sectional area, $\mu$ =viscosity, and $\Delta p$ =pressure differential across the thickness $\Delta x$ . For radial flow into a cylindrical borehole,

$q=({\frac {k}{\mu }})2\pi rh({\frac {\partial p}{\partial r}})$ ,

where r=radial distance and h=height of the cylinder.