area rule


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area rule

[′er·ē·ə ‚rül]
(aerospace engineering)
A prescribed method of design for obtaining minimum zero-lift drag for a given aerodynamic configuration, such as a wing-body configuration, at a given speed.

area rule

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A prescribed method of design for obtaining minimum zero-lift drag for a given aerodynamic configuration, such as a wing-body configuration, at a given speed. For a transonic body, the area rule is applied by subtracting from, or adding to, its cross-sectional area distribution normal to the airstream at various stations so as to make its cross-sectional area distribution approach that of an ideal body of minimum drag. For a supersonic body, the sectional areas are frontal projections of areas intercepted by planes inclined at the Mach angle. In an aircraft, the cross-sectional area along the length of an aircraft should be kept as uniform as possible and with no abrupt changes. The cross section of the fuselage is reduced in the neighborhood of the wing root junction to compensate for the cross-sectional area of wings, with the consequent reduction of wave drag.
References in periodicals archive ?
If you're the unlucky person who has to sit next to sticky-fingers' keyboard, talk to your boss and make sure that there's a clean desk/office area rule in place.
Pupils will sit just eight GCSEs in Year 11, experience a longer school day, attend over four terms rather than three and the state-school catchment area rule is eschewed in favour of a North East-wide intake.
This maddening rush to sign established or promising domestic players has hit the IPL catchment area rule for a six, with one prominent team official describing the stipulation as a " mere tokenism".
Described as the most significant aerodynamic contributor of the second half of the 20th century, the NASA Langley engineer's major accomplishments include area rule fuselage and supercritical wing designs.
His designs, particularly "the area rule," allowed supersonic flight to evolve from a closely guarded military secret to commercial use.
Like the sector method, this approach involves deductive reasoning, and although refinement is again needed to make it a mathematically acceptable proof, it is a highly appropriate method to justify the circle area rule at this level.
Since he developed the rule, the area rule is incorporated into the development of almost every American supersonic aircraft.
Without the knowledge of area rules, artwork checks can apply either the fabrication or area rule values to the entire board.
And in December, the FAA finalized its Special Flight Rules Area rule for the Washington, D.
If students are unable to remember the area rule for a particular special quadrilateral, they should be able to call on an appropriate dissection method.
Shadow education secretary Tim Yeo said he would scrap the catchment area rule which allows schools to discriminate in favour of local children because it had led to "selection by postcode".