Design of an Airframe Integrated 3-D Scramjet and Experimental Results at a Mach 10 Flight Condition

摘要

Shock tunnel experiments have been conducted within The University of Queensland's T4 Stalker Tunnel with a small airframe-integrated three-dimensional scramjet engine. The goal of the investigation was to examine the influence of airframe integration on the engine operation. The tests were conducted at a condition replicating flight at Mach 10.4 and a dynamic pressure of 48 kPa. The internal flowpath featured a rectangular-to-elliptical shape transition (REST) inlet designed for flight at Mach 12. An elliptical combustor with a constant area and diverging section and a three-dimensional nozzle completed the internal fiowpath. This fiowpath was integrated with a forebody and streamlined external geometry to provide the test model. Gaseous hydrogen fuel was injected either through portholes on the inlet, from a series of portholes behind a rearward facing step at the combustor entrance, or a combination of the two. It was found that the inlet-only and combined fuel injection schemes both produced steady combustion pressure rise without the use of ignition aids. No combustion was observed for the step-only fuelling scheme. The integration of the REST inlet with an appropriate vehicle forebody was not found to adversely affect the operation of the engine.