Vökvafasla

Vökvafasla refers to the velocity of a fluid—how fast and in what direction liquid moves at a given point and time. In physics and engineering it is described by a velocity field v(x,t), where each position x and time t is assigned a vector indicating speed and direction. The magnitude |v| is the speed, and the vector points along the instantaneous flow direction.

If density is constant, the flow is incompressible and the velocity field must satisfy the continuity equation ∇·v = 0. The motion is governed by the Navier–Stokes equations, which balance inertial effects with pressure, viscous forces, gravity, and external forces. The units of v are metres per second (m/s).

Volumetric flow rate, Q, is the amount of fluid passing through a cross-section per unit time and relates to the velocity field by Q = ∫A v·n dA. When velocity is uniform across the section, Q = vA.

Measuring vökvafasla employs tools such as pitot tubes, anemometers, laser Doppler velocimetry, and particle image velocimetry (PIV). In practice, vökvafasla is central to fluid dynamics in applications ranging from aerodynamics and hydraulics to cardiovascular physiology and oceanography.

Etymology: vökvi means liquid; fasla denotes flow or movement.