No abstract

This paper reviews important advances in understanding and predicting the behavior of scramjet combustion systems since the classic article published in this series by Antonio F e d (1973). The review focuses on basic fluid phenomena and is divided into three distinct sections. The first briefly describes progress that has been made in the design and demonstration of practical scramjets around the world, especially in the US, the FSU, France, and Germany. The second provides a contemporary exposition of the aerothermodynamics of the dual-mode ramjetkcramjet combustion system, accounting for the role of the isolator in preventing unstart from either thermal choking or flow separation due to heat release. The third part summarizes the current state of knowledge regarding fuelair mixing in dual-mode ramjetkcramjet combustors, especially the potential of axial vorticity to increase mixing effectiveness over that of lateral vorticity. 'The US Government has the right to retain a nonexclusive, royalty-free license in and to any 323 copyright covering this paper.

A simplified method of estimating the performance of ,upersonic combustion ramjet envines is presented. The method utilizes stream thrust concepts 4nd mn bles valid periormance estimates 'o be made without the aid of a computer program; only a few simple graphs are required. A new "referenc' stream thrust quantity is defined and showi. to be of value in estimatir.j engine flight performance. The data giver in this report enable perf&,r-ance estimates .to be ma*i. f:-hydrogen fueled engines oleratinig stoichionmetrically for speeds In excess of dbout Mach 8.

ProlegomenaThe early decades of aviation were characterized by the pursuit of speed and altitude, range, and extended range at high flight speeds.A major push for higher speed was initiated by the X-series of aircraft that explored the supersonic flight regime in the 1950s and 1960s.