A Century of Ramjet Propulsion Technology Evolution

TLDR

Ramjet and scramjet propulsion has evolved from subsonic to hypersonic speeds, maturing for military and space applications while leaving future opportunities open. This review surveys the worldwide evolution of ramjet propulsion since the Wright brothers. The paper examines ramjet, scramjet, and mixed‑cycle engines, their operation, rationale, and the development history of key programs. Key air‑breathing technologies that enabled ramjet maturation are identified, the current state is summarized and compared to 1980, and the present status of ramjet/scramjet technology is outlined.

Abstract

A general review is presented of the worldwide evolution of ramjet propulsion since the Wright brothers e rst turned man’ s imagination to e y into a practical reality. A perspective of the technological developments from subsonic to hypersonic e ight speeds is provided to allow an appreciation for the advances made internationally from the early 1900s to current times. Ramjet, scramjet, and mixed-cycle engine types, and their operation and rationale for use are considered. The development history and principal contributing development programs are reviewed. Major airbreathing technologies that had signie cant impact on the maturation of ramjet propulsion and enabled engine designs to mature to their current state are identie ed. The general state of e ight-demonstrated technology is summarized and compared with the technology base of 1980. The current status of ramjet/scramjet technology is identie ed. Ramjet and scramjet propulsion technology has matured dramatically over the years in support of both military and space access applications, yet many opportunities remain to challenge future generations of explorers.