Mach cone
Mach cone
[′mäk ‚kōn]Mach Cone
a conical surface that bounds the region in a supersonic flow of gas in which the sound waves (perturbations) emanating from a point source A of the perturbations are concentrated (see Figure 1). In a homogeneous supersonic flow of gas, the angle a between the generatrices of the Mach cone and its axis is called the Mach angle; it is related to the Mach number by the equation sin a = 1/M