North American XB-70A Valkyrie in flight 061122-F-1234P-022

aerodynamics Aerodynamics () is the study of the motion of atmosphere of Earth, air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dynamics and its subfield of gas dynamics, and is an ...

, compression lift refers to the increased pressure under an

aircraft An aircraft ( aircraft) is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or the Lift (force), dynamic lift of an airfoil, or, i ...

that uses

shock wave In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a me ...

s generated by its own

supersonic Supersonic speed is the speed of an object that exceeds the speed of sound (Mach 1). For objects traveling in dry air of a temperature of 20 °C (68 °F) at sea level, this speed is approximately . Speeds greater than five times ...

flight to generate

lift Lift or LIFT may refer to: Physical devices * Elevator, or lift, a device used for raising and lowering people or goods ** Paternoster lift, a type of lift using a continuous chain of cars which do not stop ** Patient lift, or Hoyer lift, mobile ...

. This can lead to dramatic improvements in lift for

hypersonic In aerodynamics, a hypersonic speed is one that exceeds five times the speed of sound, often stated as starting at speeds of Mach 5 and above. The precise Mach number at which a craft can be said to be flying at hypersonic speed varies, since i ...

aircraft.

Clarence Syvertson Clarence A. "Sy" Syvertson (1926 – September 13, 2010) was the Center Director of the Ames Research Center of the National Aeronautics and Space Administration, located at Moffett Field, California. Biography Early life, education, and mi ...

and

Alfred J. Eggers Alfred J. Eggers, Jr. (June 24, 1922 – September 22, 2006) was NASA's Assistant Administrator for Policy. He devoted efforts to determine the influence of aviation technology in world peace and lectured widely. Eggers specialized in hypers ...

discovered this phenomenon in 1956 as they analyzed abnormalities at the reentry of

nuclear warhead A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear expl ...

s.Compression Lift
/ref> The basic concept of compression lift is well known; " planing" boats reduce drag by "

surfing Surfing is a surface water sport in which an individual, a surfer (or two in tandem surfing), uses a board to ride on the forward section, or face, of a moving wave of water, which usually carries the surfer towards the shore. Waves suita ...

" on their own

bow wave A bow wave is the wave that forms at the bow (watercraft), bow of a ship when it moves through the water. As the bow wave spreads out, it defines the outer limits of a ship's Wake (physics), wake. A large bow wave slows the ship down, is a risk t ...

in exactly the same fashion. Using this effect in aircraft is more difficult, however, because the "wake" is not generated until supersonic speeds are reached, and is highly angled. Aircraft have to be carefully shaped to take full advantage of this effect. In addition, the angle of the

s varies greatly with speed, making it even more difficult to design a craft that gains significant lift over a wide range of speeds. Higher speed designs using compression lift,

waverider A waverider is a hypersonic aircraft design that improves its supersonic lift-to-drag ratio by using the shock waves being generated by its own flight as a lifting surface, a phenomenon known as compression lift. The waverider remains a w ...

s, remain an interesting possibility for

vehicle designs, although only testbed models have been flown. The Boeing X-51 (Waverider) also uses compression lift.

References

External links

The Bird is on the Wing: Aerodynamics and the Progress of the American AirplaneThe Story of the Boeing Company By Bill Yenne, William YenneBomber R&D Since 1945: The Role of Experience By Mark A. Lorell, Alison SaundersHypersonic Vehicle Design
Aerodynamics {{Aviation-stub

See also

References

External links