relative Mach number
Also found in: Dictionary, Thesaurus, Medical.
Related to relative Mach number: Critical Mach number
relative Mach number[′rel·əd·iv ′mäk ‚nəm·bər]
The ratio of the velocity of a body to that of sound in a surrounding medium. A Mach number of 0.8 or 1.2 means that the aircraft is flying at 0.8 or 1.2 times, respectively, the local speed of sound at that ambient temperature. Also known as a relative Mach number.