Last March, NASA announced that as part of its New Aviation Horizons initiative, Lockheed Martin had been chosen to develop a manned demonstrator aircraft called the Quiet Supersonic Technology (QueSST) X-plane. It would be used to test technologies that would make commercial supersonic aircraft quiet enough to fly over land. Eleven months later, Lockheed and the agency are ready to take the next step as a nine-percent scale model starts wind tunnel tests at the Glenn Research Center in Cleveland.
NASA says that the bespoke metal model will spend the next eight weeks in the 8 x 6 ft (2.4 x 1.8 m) Supersonic Wind Tunnel, which is capable of subjecting the QueSST to wind speeds from Mach 0.3 to Mach 1.6 (about 150 to 950 mph, 241 to 1,530 km/h) as the engineers learn more about the aircraft's aerodynamics and propulsion system.
According to aerospace engineer Ray Castner, the tests will include measurements of QueSST's lift, drag, and side forces as well as how the air moves around the engine nacelles. The idea is to subject the model to all the conditions from takeoff to supersonic cruising to landing, using the variability of Glenn's tunnel.
The purpose of QueSST, which is still in the early stages of design, is to create a supersonic airplane that is able to spread out its shock wave in such a way that when it reaches the ground it's heard as a soft thump rather than an ear-shattering boom.
The wind tunnel tests are scheduled to continue until the middle of this year. If successful and the funding is available, the mature design will then go on to final design, fabrication, and testing.
"Our unique aircraft design is shaped to separate the shocks and expansions associated with supersonic flight, dramatically reducing the aircraft's loudness," says Peter Losifidis, QueSST program manager at Lockheed Martin Skunk Works. "Our design reduces the airplane's noise signature to more of a 'heartbeat' instead of the traditional sonic boom that's associated with current supersonic aircraft in flight today."
The video below shows the wind tunnel model being assembled.