Wind tunnel

Wind tunnel, structure in which a controlled stream of air is produced in order to observe the effects on scale models or full-size components of airplanes, missiles, automobiles, or such structures as bridges and skyscrapers. An important research tool in aerodynamics, the wind tunnel enables a design to be accurately tested without the risks attached to full-scale trials. Hypersonic wind tunnels, operating on an impulse principle, can simulate the frictional effects of flight at over 5 times the speed of sound.

See also: Aerodynamics.