 Hayes similitude principle

The Hayes similitude principle enabled aerodynamicists to take the results of one series of tests or calculations and apply them to the design of an entire family of similar configurations where neither tests nor detailed calculations are available.The similitude principle was developed by Wallace D. Hayes, a pioneer in hypersonic flow, which is considered to begin at about five times the speed of sound, or Mach 5, and is described in his classic book Hypersonic Flow Theory co-written with Ronald Probstein and first published in 1959.