Inlets, exits, and cooling problems. 1 - Inlets

As design flight speeds are pushed progressively higher, the supersonic inlet becomes an increasingly important component of air-breathing propulsion systems. Currently, the turbojet engine is being considered for application at Mach numbers up to approximately 4 and the ramjet engine for application in the hypersonic region, or Mach numbers of 5 and above. Herein the inlet situation is surveyed and the merits of the various inlet-design philosophies are assessed on the basis of recent experimental data obtained at Mach numbers up to 5.