Air brake (aeronautics)
An air brake is extendable into the air flow valve to a vehicle, which increases the flow resistance of the air.
The effected by an air brake resistance increase can be done by increasing the face or by increasing the cw value. Thereby, the parasitic resistance is increased. Since after the air brakes tearing the laminar flow on the wing, is also reduced buoyancy.
Air brakes on airplanes
Air brakes are used in aircraft to decrease the angle of attack at higher flying speed to increase the rate of descent, or to decrease the roll distance at the landing. In military aircraft, the air brake for tactical maneuvers (eg Cobra maneuver) or applied to reduce the speed in a dive ( dive brakes). Air brakes are sometimes on the wing upper surface, sometimes attached to the top and bottom. They are most effective in about 25 to 45% of the wing chord and drive there vertically out from the profile. They interfere in the extended state, the air flow on the wing, destroying lift and generate resistance. They are used in order to avoid undesirable high speed and, particularly during landing, in order to increase the rate of descent and to reduce the glide ratio. A special form of said spoiler is Endkantendrehklappe, in which the rear part of the profile is rotated into the air stream, thus creating resistance.
Among the single-engine light aircraft usually have only high quality, faster, mostly turbocharged models such as the Mooney M20 or the Columbia 400 is an air brake. In almost all of glider types ( except, for example, Lo 100 ) Air brakes are used as landing aid. Civilian aircraft with jet engines on the other hand have spoilers ( spoilers ).
The airbrakes are extended either mechanically or hydraulically from the top or bottom or both sides of the wings of airplanes. Especially in combat aircraft also airbrakes occur that put - out or bottom of the fuselage, or be deployed in pairs symmetrically from the hull side walls.
Air brakes on cars
In rare cases, air brakes are also built on land vehicles, for example, the Mercedes 300 SLR and Bugatti Veyron 16.4 (dedicated air brake) and the Mercedes- Benz SLR McLaren ( rear spoiler as an air brake ). The McLaren MP4 -12C 2011 put into production the high -folding rear wing also acts as an air brake.
Air brakes on trains
The Japanese FASTECH 360, prototype of the high-speed range E5 had an emergency brake system with air brakes.