Ignition of turbulent non-premixed flames

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.

https://bemil.chosun.com/brd/files/BEMIL064/upload/Ronald%20Ramjet%20review%20p27.pdf

A Century of Ramjet Propulsion Technology Evolution

Transverse jets and their control

The development of scramjet propulsion for alternative launch and payload delivery capabilities has been composed largely of ground experiments for the last 40 years. With the goal of validating the use of short duration ground test facilities, a ballistic reentry vehicle experiment called HyShot was devised to achieve supersonic combustion in flight above Mach 7.5. It consisted of a double wedge intake and two back-to-back constant area combustors; one supplied with hydrogen fuel at an equivalence ratio of 0.34 and the other unfueled. Of the two flights conducted, HyShot 1 failed to reach the desired altitude due to booster failure, whereas HyShot 2 successfully accomplished both the desired trajectory and satisfactory scramjet operation. Postflight data analysis of HyShot 2 confirmed the presence of supersonic combustion during the approximately 3 s test window at altitudes between 35 and 29 km. Reasonable correlation between flight and some preflight shock tunnel tests was observed.

Flight Data Analysis of the HyShot 2 Scramjet Flight Experiment

Jet fuel ignition delay times: Shock tube experiments over wide conditions and surrogate model predictions

Ageneralreviewoftheemergenceandmaturingofsupersoniccombustionramjet (scramjet)enginetechnologies overthelast 40 years is presented. The review isgiven in terms of theeffortscompleted or proceeding in theUnited States, Russia, France, Germany, Japan, Australia, and other countries. A brief account of the challenges of scramjet combustor development is given, and attention is directed toward other source references for more detailed accounts of technology evolution. Two emerging scramjet applications are identie ed, namely, hydrogenfueledhigh-speed engines foraccess to spaceand hydrocarbon-fueled enginesforhypersonicair-launched missiles.

Edward T. Curran

Papers

Scramjet Engines: The First Forty Years