Volumetric flux
In fluid dynamics, the volumetric flux is the rate of volume flow across a unit area (m·s·m). Volumetric flux = liters/(second*area). 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.