flutter

(redirected from fluttery)
Also found in: Dictionary, Thesaurus, Medical, Idioms.

flutter

1. Pathol an abnormally rapid beating of the auricles of the heart (200 to 400 beats per minute), esp in a regular rhythm, sometimes resulting in heart block
2. Electronics a slow variation in pitch in a sound-reproducing system, similar to wow but occurring at higher frequencies
3. Aeronautics a potentially dangerous oscillation of an aircraft, or part of an aircraft, caused by the interaction of aerodynamic forces, structural elastic reactions, and inertia
4. Music a method of sounding a wind instrument, esp the flute, with a rolling movement of the tongue
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Flutter

 

in aeroelasticity, self-excited oscillations of parts of an aircraft, mainly the wing and the tail, that occur when the critical flutter speed is reached. Flutter may result in structural failure. Flutter is associated with the relative location of the center of gravity and the center of twist of the wing or tail and with other characteristics of a given aircraft.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

flutter

[′fləd·ər]
(acoustics)
Distortion that occurs in sound reproduction as a result of undesired speed variations during the recording, duplicating, or reproducing process.
(electromagnetism)
A fast-changing variation in received signal strength, such as may be caused by antenna movements in a high wind or interaction with a signal or another frequency.
(engineering)
The irregular alternating motion of the parts of a relief valve due to the application of pressure where no contact is made between the valve disk and the seat.
(fluid mechanics)
(medicine)
Rapid, regular contraction of the atrial muscle of the heart.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

Flutter (aeronautics)

An aeroelastic self-excited vibration with a sustained or divergent amplitude, which occurs when a structure is placed in a flow of sufficiently high velocity. Flutter is an instability that can be extremely violent. At low speeds, in the presence of an airstream, the vibration modes of an aircraft are stable; that is, if the aircraft is disturbed, the ensuing motion will be damped. At higher speeds, the effect of the airstream is to couple two or more vibration modes such that the vibrating structure will extract energy from the airstream. The coupled vibration modes will remain stable as long as the extracted energy is dissipated by the internal damping or friction of the structure. However, a critical speed is reached when the extracted energy equals the amount of energy that the structure is capable of dissipating, and a neutrally stable vibration will persist. This is called the flutter speed. At a higher speed, the vibration amplitude will diverge, and a structural failure will result. See Aeroelasticity

Aircraft manufacturers now have engineering departments whose primary responsibility is fluffer safety. Modern flutter analyses involve extensive computations, requiring the use of large-capacity, high-speed digital computers. Flutter engineers contribute to the design by recommending stiffness levels for the structural components and control surface actuation systems and weight distributions on the lifting surfaces, so that the aircraft vibration characteristics will not lead to flutter within the design speeds and altitudes. See Airframe, Wing

McGraw-Hill Concise Encyclopedia of Engineering. © 2002 by The McGraw-Hill Companies, Inc.

flutter

flutter
The wing twist as it flaps up and down. This up and down motion causes changes in the angle of attack. The changes in angle of attack mean that the aerodynamic forces are always tending to help the motion, which do not, therefore, damp out, resulting in flutter.
A vibration caused by the combined effects of the changes in pressure distribution over the surface of airfoils as the angle of attack is altered and the elastic forces set up by the distortion of the structure itself. In the worst cases, there may be a total loss of control and a consequent crash. The flutter may affect the control surfaces such as an aileron, or the main planes, or both. The flutter can be avoided by using mass balances, increasing structural rigidity, and having irreversible controls. Flutter also occurs with propellers, compressor blades, and turbine blades. Flutter is an aeroelastic self-excited vibration in which the external source of energy is the airstream. It depends on the elastic, inertial, and dissipative forces of the system in addition to the aerodynamic forces.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved
References in periodicals archive ?
A fluttery tunic looks utterly romantic with red stirrup leggings and lace-up booties.
For fluttery eyelashes, Birmingham beauty Cat Deeley relies on SUQQU Mascara Base, pounds 22 (Selfridges).
We cruised to the Elephant's Trunk in the Fifth Street Public Market, where we found a musical fluttery skirt, lavender wings for a flower princess and even some knightly armor for the tomboys, real boys or girls who don't want you to know they're wearing a training bra.
Two key moments reveal the importance of remastering: a snowstorm halfway in made even more fluttery and feathery, and the penultimate scene's raging fire ever more passionate--and indicative of the studio's thereafter fascination with heroism in the face of peril.
Cleopatra was a platinum-blonde Jean Harlow look-alike who donned a skin-tight black-and-white dress and, surrounded by tuxedo-clad chorus boys, slinkily descended a staircase to vamp Caesar with the sensuous "V'adoro pupille." For his Fred Astaire-style song-and-dance number, in which he played duelling roulades with an onstage violinist in white tails, Cesare (who made his first-act entrance sporting a red uniform and riding on a tank) changed into top hat and black tails behind a gaggle of fluttery chorines dressed as French maids.
Works like the oval floral fete gallante, nymphea, 2002, or feverish embarkation, 2001, allude to the fluttery brushwork of a Fragonard or Watteau while working it up into something far more frantic and febrile.
Unfortunately, we're not all blessed with perfect arched eyebrows and fluttery lashes - and let's not forget the everyday problems such as dark circles, puffiness and under-eye bags.
The iridescent flash of hummingbirds' wings, the fluttery beauty of butterflies, and the friendly buzz of bees can bring a garden alive.
To the sound of clanging bells and the bark of Japanese merchants, Karp moved meditatively, her gestures fluttery and quick, as if counting change.
Ralph Fiennes makes a wonderful Oscar, a fluttery matchstick man with flame red hair.
that will comfort her and smell the dark, fluttery grass under her arms.
The person suffers arrhythmia, a fluttery heartbeat that pumps insufficient blood to the brain, and faints.