Hydrogen scramjet with side wall injection

Abstract

Preliminary results are presented from an experimental evaluation of a hydrogen-burning wall-injection scramjet engine, performed in the free-piston shock tunnel at the Australian National University. The advantages of scramjet propulsion for high-Mach-number high-altitude flight are reviewed, and the need for an alternative to injection struts is indicated. Pressure profiles and heat-transfer measurements for constant-area and diverging ducts are presented graphically and characterized in detail. The ability of the injected flow to shield the chamber wall from the heat of the freestream flow is demonstrated. The extrapolation of the shock-tunnel results to flight conditions, however, is made difficult by the fact that a significant amount of fuel passes through a quenched zone without burning, seriously degrading overall performance.