Before revision: Δp = poutlet - pinlet = pb - pa. = Δp/L = hydraulic gradient applied between the points a and b. Darcy's law, as refined by Morris Muskat, in the absence of gravitational forces and in a homogeneously permeable medium, is given by a simple proportionality relationship between the instantaneous flux (units of : m3/s, units of : m2, units of : m/s) through a porous medium, the permeability of the medium, the dynamic viscosity of the fluid , and the pressure drop over a given distance , in the form This equation where is the hydraulic gradient and is the instantaneous volumetric flux.Notice that the quantity , often referred to as the Darcy flux or Darcy velocity, is not the velocity at which the fluid is travelling through the pores.
After revision: Δp = poutlet - pinlet = pb - pa. = Δp/L = hydraulic gradient applied between the points a and b. Darcy's law, as refined by Morris Muskat, in the absence of gravitational forces and in a homogeneously permeable medium, is given by a simple proportionality relationship between the instantaneous flux (units of : m3/s, units of : m2, units of : m/s) through a porous medium, the permeability of the medium, the dynamic viscosity of the fluid , and the pressure drop over a given distance , in the form Which can be generalised to a local form: where is the hydraulic gradient and is the instantaneous volumetric flux.Notice that the quantity , often referred to as the Darcy flux or Darcy velocity, is not the velocity at which the fluid is travelling through the pores.