Volumetric flux

In fluid dynamics, the volumetric flux is the rate of volume flow across a unit area (m³·s⁻¹·m⁻²). The density of a particular property in a fluid's volume, multiplied with the volumetric flux of the fluid, thus defines the advective flux of that property. The volumetric flux through a porous medium is often modelled using Darcy's law.

Volumetric flux is not to be confused with volumetric flow rate, which is the volume of fluid that passes through a given surface per unit of time (as opposed to a unit surface).