Mach number

views updated

Mach number Ratio of the speed of a body or fluid to the local speed of sound. Mach 1 refers to the local speed. An aircraft flying below Mach 1 is said to be subsonic. supersonic flight means flying at speeds above Mach 1. Mach numbers are named after the Austrian physicist Ernst Mach (1838–1916).

More From encyclopedia.com