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Hydraulic Conductivity

  The Hydraulic Conductivity is the factor of proportionality in Darcy's flow equation. It is a function of both the fluid and the porous medium through which the fluid is flowing. It can be expressed as:

where 

K               = hydraulic conductivity [LT]


k 		= intrinsic permeability [L]


g 		= gravitational constant [LT]


v 		= kinematic viscosity of the fluid [LT]
The intrinsic permeability or what is commonly referred to now as the permeability is independent of the fluid and depends only on the porous medium. The permeability property is:

where 

k         = intrinsic permeability [L]


c         = constant (This constant is dimensionless and is controlled by factors other than the 

            diameter of the grains in the porous medium,

            such as packing, distribution and shape)


d         = mean grain diameter [L]

k has a high value for high porosity mediums (sands, gravels) and a low value for low porosity mediums (silts, clay).


Rhonda Macleod
Mon Apr 17 16:32:58 EDT 1995