300px|thumb|upright=1.14|Aftermarket Micro AeroDynamics vortex generators mounted on the wing of a [[Cessna 182 Skylane#Variants|Cessna 182K]]

thumbnail|Sketch describing how vortex generators improve flow characteristics on a wind turbine

thumb|1967 Model [[Cessna 182K in flight showing after-market vortex generators on the wing leading edge]]

thumb|[[A-4SU Super Skyhawk|TA-4SU Super Skyhawk showing the row of vortex generators on the drooped leading edge slats.]]

thumb|right|The [[Symphony SA-160 was designed with two unusual vortex generators on its wing to ensure aileron effectiveness through the stall]]

A vortex generator (VG) is an aerodynamic device, consisting of a small vane usually attached to a lifting surface (or airfoil, such as an aircraft wing) VGs may also be attached to some part of an aerodynamic vehicle such as an aircraft fuselage or a car. When the airfoil or the body is in motion relative to the air, the VG creates a vortex, which, by removing some part of the slow-moving boundary layer in contact with the airfoil surface, delays local flow separation and aerodynamic stalling, thereby improving the effectiveness of wings and control surfaces, such as flaps, elevators, ailerons, and rudders. and wind turbine blades. On both aircraft and wind turbine blades they are usually installed quite close to the leading edge of the aerofoil in order to maintain steady airflow over the control surfaces at the trailing edge. also delay flow separation at high angles of attack by re-energizing the boundary layer. Aftermarket suppliers claim (i) that VGs lower stall speed and reduce take-off and landing speeds, and (ii) that VGs increase the effectiveness of ailerons, elevators and rudders, thereby improving controllability and safety at low speeds. For home-built and experimental kitplanes, VGs are cheap, cost-effective and can be installed quickly; but for certified aircraft installations, certification costs can be high, making the modification a relatively expensive process.

Owners have reported that on the ground, it can be harder to clear snow and ice from wing surfaces with VGs than from a smooth wing, but VGs are not generally prone to inflight icing as they reside within the boundary layer of airflow. VGs may also have sharp edges which can tear the fabric of airframe covers and may thus require special covers to be made. until 1991,

the one-engine-inoperative climb requirement for multi-engine airplanes with a maximum takeoff weight of or less was as follows:

where <math>V_{s0}</math> is the stalling speed in the landing configuration in miles per hour.

Installation of vortex generators can usually bring about a slight reduction in stalling speed of an airplane An increase in maximum weight allowed by structural requirements can usually be achieved by specifying a maximum zero fuel weight or, if a maximum zero fuel weight is already specified as one of the airplane's limitations, by specifying a new higher maximum zero fuel weight.

See also

  • Index of aviation articles
  • Turbulator
  • Boundary layer suction
  • Boundary layer control
  • Circulation control wing

References

  • Kermode, A.C. (1972), Mechanics of Flight, Chapter 11, page 350 - 8th edition, Pitman Publishing, London
  • Clancy, L.J. (1975), Aerodynamics, Pitman Publishing, London
  • Vortex Generators: 50 Years of Performance Benefits, a history of VGs