Strömungsbeschleunigung
Strömungsbeschleunigung, or flow acceleration, is a central quantity in fluid dynamics describing how the velocity of a fluid element changes with time as it moves through a flow field. It combines local and convective contributions: a = Du/Dt = ∂u/∂t + (u · ∇)u, where u is the velocity vector field. The local (temporal) term ∂u/∂t accounts for changes at a fixed point, while the convective term (u · ∇)u accounts for changes due to movement through spatial variations in the velocity field. The material derivative Du/Dt follows a specific fluid parcel, contrasting with Eulerian descriptions that fix a point in space.
In the Navier-Stokes framework, the acceleration of a Newtonian fluid is related to forces by ρ Du/Dt =
Measurement and computation: acceleration can be obtained directly from time-resolved velocity fields using particle image velocimetry
See also: Navier-Stokes equations, Euler equations, turbulence, convection, local and convective acceleration.