Vortex Pair - Uzui

...So if we take two parallel isolated straight vortices, they will move in a circular motion around an axis that can be called the center of gravity of their strength. In particular, a pair of vortices with opposite directions and equal strength, such as those seen when a cylinder is suddenly accelerated in a fluid, is called a vortex pair, and they move in parallel motion perpendicular to the plane connecting the two. When the speed of the cylinder is high and many vortices are generated to form a vortex street, the symmetrical arrangement is unstable, and they are generated alternately and lined up in a staggered manner. ...

*Some of the terminology that refers to "vortex pairs" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…そこで二つの平行な孤立直線渦をとれば，両者の強さの重心ともいうべき軸のまわりを円運動する。とくに流体中で円柱が急発進したときに見られるような向きが反対で強さが等しい1対の渦は渦対と呼ばれ，両者を結ぶ平面に垂直に併進運動する。円柱の速さが大きく，多数の渦が発生して渦列を作るときは，対称な配置のものは不安定で，交番して発生して互い違いに並ぶ。…

※「渦対」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