Turbulent

Turbulent is an adjective used to describe processes or environments marked by disorder, rapid fluctuations, or agitation. It is commonly used in physics and engineering to describe fluid motion, but it can also describe unstable conditions in weather, markets, or social life.

The word derives from Latin turbulentus, from turba meaning crowd or disturbance, via Old French turbulente, and entered English in the early modern period.

In fluid dynamics, turbulence is a state in which fluid motion is chaotic and characterized by fluctuating velocities, pressures, and swirling eddies. It typically arises when inertial forces exceed viscous forces, often at high Reynolds numbers. Turbulent flows exhibit a wide range of interacting scales and an energy cascade from large to small eddies. Modeling turbulent flows commonly uses approaches such as Reynolds-averaged Navier–Stokes equations, large-eddy simulation, and direct numerical simulation.

In other domains, turbulence describes periods of severe disturbance. Turbulent weather includes strong winds and storms; turbulent seas describe rough ocean conditions. In economics or politics, turbulence denotes periods of instability, rapid change, or upheaval.

See also: turbulence, laminar flow, Reynolds number.