Definitions for "mach number"
The ratio of the speed of a moving body to the speed of sound.
Ratio of wave or flow speed to speed of sound. Supersonic waves or flows have M 1, this is true for detonations or shock waves. Subsonic waves or flows have M 1, this is true for most flames.
The ratio of the speed of an object to the local speed of sound. abbreviation: M Fr: nombre de Mach