stromingsflux

Stromingsflux is a Dutch term used to denote the flux associated with a flowing quantity passing through a surface per unit time. In physics and engineering, flux is the surface integral of a vector field representing a flowing quantity across a surface. For a vector field F representing the flow, the stromingsflux through a surface S is Φ_S = ∮_S F · n dS, where n is the unit normal to S. For a closed surface, Gauss's (divergence) theorem relates Φ to the volume integral of ∇·F: Φ = ∭_V ∇·F dV. If F is the velocity field v of an incompressible fluid and ρ is density, the volumetric or mass flux can be written as Φ_S = ∮_S v · n dS or Φ_S = ∮_S ρ v · n dS, respectively. In electromagnetism and heat transfer, the same formalism applies with appropriate F: the electric charge flux density J and the Poynting vector S for energy flux.

Stromingsflux is therefore a general concept describing how much of a quantity crosses a surface per unit time. It is central in transport phenomena, continuity equations, and conservation laws, and is applied across hydrology, meteorology, chemical engineering, and physics.

The term is used primarily in Dutch-language scientific literature; in English contexts the term "flux" or "throughput" is common, with the same mathematical meaning.