fluid dynamics In physics, physical chemistry and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids – liquids and gases. It has several subdisciplines, including (the study of air and other gases in motion ...

, the volumetric flux is the rate of volume flow across a unit area. It has dimensions of distance per time (or volume per time-area), equivalent to mean velocity. Its

SI unit The International System of Units, internationally known by the abbreviation SI (from French ), is the modern form of the metric system and the world's most widely used system of units of measurement, system of measurement. It is the only system ...

is m³·s⁻¹·m⁻² or m·s⁻¹. 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 called ''

superficial velocity Superficial velocity (or superficial flow velocity), in engineering of multiphase flows and flows in porous media, is a hypothetical (artificial) flow velocity calculated as if the given phase or fluid were the only one flowing or present in a gi ...

'' and it is often modelled using Darcy's law. Volumetric flux is not to be confused with

volumetric flow rate In physics and engineering, in particular fluid dynamics, the volumetric flow rate (also known as volume flow rate, or volume velocity) is the volume of fluid which passes per unit time; usually it is represented by the symbol (sometimes \do ...

, which is the volume of fluid that passes through a ''given'' surface per unit of time (as opposed to a ''unit'' surface).

References

Physical quantities Vector calculus Fluid dynamics {{fluiddynamics-stub