Mach wave Mach wave In fluid dynamics, a Mach wave is a pressure wave traveling with the speed of sound caused by a slight change of pressure added to a compressible flow. These weak waves can combine in supersonic flow to become a shock wave if sufficient Mach waves are present at any location. Such a shock wave is called a Mach stem or Mach front. Thus, it is possible to have shockless compression or expansion in a supersonic flow by having the production of Mach waves sufficiently spaced ("cf." isentropic compression in supersonic flows). A Mach wave is the weak limit
Ford Mustang Mach 1 (without Ram Air) remained optional on every model. Chart does not reflect the Boss 351 variant of the 351 Cleveland or 250cid I6, as neither were available in the Mach 1 package. The 1972 R-code 351HO package - essentially the solid-lifter Boss 351 motor from 1971 with a reduction in compression from 11.0:1 to 8.8:1 - is listed here, as it was available with the Mach 1 package that year. The Mach 1 name continued with the advent of the Mustang II in 1974. The downsized vehicle - fitted with the 2.8 L V6 rated at - outsold the Mach