Sat, Aug 02, 2003

USAF Displays Experimental Pulsed Detonation Engine -- On Long-EZ

Using automotive technology and a little bit of “magic,” researchers at the Air Force Research Laboratory’s propulsion directorate demonstrated their latest experiment at the Experimental Aircraft Association’s AirVenture airshow.

For years, propulsion researchers around the world have searched for a better, more efficient way to increase speed and improve the performance of aircraft. Propulsion scientists from the lab at Wright-Patterson Air Force Base, Ohio, have developed the pulsed-detonation engine, made up mostly of off-the-shelf automotive parts.

According to Dr. Fred Shauer, the engine’s creator, the system creates propulsion by using a series of controlled explosions of fuel and air in detonation tubes that look like long exhaust pipes. The “magic” is the process Shauer’s team has developed to burn the fuel and air in a way that increases the intensity of the explosions, providing increased thrust that could power future aircraft to speeds of up to Mach 4.

The system uses any type of general-aircraft fuel and even can be powered by regular unleaded gas used in cars, he said. To develop the propulsion system, there was a need for an engine to power the experiment.

“We basically used car parts because they were cheaper,” said Shauer. “Car engines also run a long time, and the valve design works well for our design.”

The experiment is designed to study different propulsion systems that could eventually be mounted on military and civil aircraft. In its final form, this type of detonation engine could make aircraft faster, lighter and more maneuverable, Shauer said.

“There is a lot of interest in this type of experimental technology at (the air show),” he said.

The aircraft used to test the pulsed-detonation engine is the Long-EZ, designed and built by Burt Rutan, most noted for the design and construction of the Voyager aircraft. His brother, Dick Rutan, and Jeanna Yaeger flew around the world in the Voyager in 1986, non-stop, without refueling. [ANN Thanks Staff Sgt. Don Nelson, AFPN]