Coefficient of contraction

...When a fluid leaves a container through its outlet, the cross-sectional area of ​​the flow that is in contact with the atmosphere approaches a value S ∞ _that is smaller than the cross-sectional area S ₀ of the outlet (Figure). The ratio k = _{S ∞} / S of S ∞ to S ₀ is called the coefficient of contraction, and has a theoretical minimum value between 0.5 and 1. If the hole is too small, the phenomenon becomes complicated due to viscosity and surface tension. ...

*Some of the terminology explanations that refer to "coefficient of contraction" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…流体が容器の流出口から出ていくとき，大気に接する流れの断面積が出口の断面積S₀よりも小さい値S_∞に漸近する現象(図)。S_∞とS₀との比k＝S_∞/Sはくびれの係数coefficient of contractionと呼ばれ，理論的な最小値0.5と1の間の値をとる。孔が細すぎると，粘性や表面張力のために現象が複雑になる。…

※「coefficient of contraction」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