November flight planned following laboratory experiments

An axisymmetric "inward-turning" supersonic-combustion ramjet (scramjet) engine that could ultimately power a hypersonic strike aircraft has been tested at Mach 5. A flight test is planned for November from Woomera in Australia.

Funded by the US Defense Advanced Research Projects Agency (DARPA), the 70-100ms test was the first of many to be conducted at the Calspan-University of Buffalo Research Center's Large Enthalpy National Shock Tunnel 2.

The engine's self-start capability at its M5 design ignition point is being investigated.

The axisymmetric, or round, design is more efficient than the rectangular, two-dimensional, scram­jet used in NASA's X-43A hypersonic experimental vehicle, which flew at M9.86 last year. The inward-turning inlet focuses the incoming airflow into the centre of the engine.

"The tests are to increase confidence that the [engine] will start at M5 when it is supposed to," said David Van Wie, principal professional staff member at Johns Hopkins University's Applied Physics Laboratory, speaking at May's American Institute of Aeronautics and Astronautics' 13th international spaceplanes and hypersonics conference in Naples.

In November, the same scramjet will be flown at M10 aboard a sounding rocket from Woomera to verify the scramjet's performance.

DARPA and Lockheed Martin are pursuing the inward-turning scramjet to power the hypersonic cruise vehicle that could emerge from the US research agency's Falcon programme to demonstrate technology for a prompt global-range strike system.

Source: Flight International