無む次じ元げん数すう

noun

dimensionless number

Technical term in mathematics and physics for a quantity without physical units, such as Reynolds number or Mach number.

• レイノルズ数すうは流りゅう体たい力りき学がくでよく使つかわれる無む次じ元げん数すうです。

  The Reynolds number is a dimensionless number often used in fluid dynamics.