variable geometry wing

Japanese: variable geometry wing（英語表記）variablegeometrywing

… A swept-back wing with a large sweep angle is advantageous because it creates less drag at high speeds, but is disadvantageous in that it produces less lift at low speeds than a straight wing with no sweep angle. For this reason, some high-performance, multipurpose military aircraft use variable-geometry wings (VG wings for short), which allow the sweep angle to be freely changed during flight so that the swept-back wing is closer to a straight wing when flying at low speeds and the swept-back wing is closer to a swept-back wing when flying at high speeds. The selection of wing type is also important for high subsonic and supersonic aircraft, and various research projects are being conducted on this topic. …

From [Wings]

…In the 1960s, variable geometry wings (wings with variable sweepback) were put into practical use. The structure and mechanism are complex and the weight is heavy, but the aspect ratio and wing thickness ratio as well as the sweepback angle can be changed by rotating the wings, so the wing shape can be adapted to the flight conditions from high to low speeds. The oblique wing is a wing in which one of the left and right integrated variable wings rotates so that the other becomes a swept wing and the other becomes a forward wing. The aim is to reduce wave resistance at supersonic speeds and increase the lift-to-drag ratio by distributing the entire wing longer forward and backward than when both wings are swept back or forward. …

*Some of the terminology explanations that mention "variable geometry wing" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…　後退角の大きな後退翼は，高速時には抗力が小さくて有利であるが，低速時には出せる揚力の値が後退角のない直線翼に比べて低く不利である。そこで高速で飛ぶときには後退翼，低速で飛ぶときには直線翼に近くなるよう，飛行中後退角を自由に変えられる可変後退翼variable geometry wing(略してVG翼)が一部の高性能多用途軍用機で使われている。　高亜音速機や超音速機では翼型の選定も重要で，いろいろな研究がなされている。…

【翼】より

…そこで翼を高速では後退翼に，低速では直線翼に回転させる構造とした可変翼(可変後退角翼)機も1960年代に実用化された。可変翼variable geometry wingはVG翼とも呼ばれ，構造，機構が複雑で重量はかさむが，翼の回転により後退角のほかアスペクト比と翼厚比も同時に変えられるので，高速から低速まで飛行状態に適した翼の形にできる。斜め翼は左右一体の可変翼を一方は後退翼，他方は前進翼となるように回転させる翼で，両翼とも後退翼あるいは前進翼とする場合よりも翼全体を前後に長く分布させ，超音速での造波抵抗を減らし揚抗比を上げるのがねらいである。…

※「variable geometry wing」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典第２版について | 情報

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