Proving an engine design is powerful enough to fly commercial passengers at supersonic speeds and quiet enough to meet future airport noise regulations is a new goal for NASA.
The Fiscal 2016 budget request released by NASA on 2 February lists a commercial supersonic engine demonstration as a key achievement planned for the next fiscal year.
NASA has spent several years focusing on demonstrating technologies for subsonic commercial aircraft, but has recently been investing more funding in supersonic aircraft technology.
The low noise propulsion for low-boom aircraft challenge has already achieved some initial success. Last year, NASA tested with contractor General Electric a design for low-noise engine nozzle.
Not only did this test show that it is likely that supersonics-capable engines can be built that exceed the [future noise] goals and meet new international noise standards, but the test also helped validate the analysis capability that can be applied to a wide variety of future designs, according to NASA budget documents released on 2 February.
A commercial supersonic aircraft faces two key regulatory challenges. First, the supersonic boom produced by flying faster than the speed of sound is banned over the USA and Europe. The only way to repeal the ban is to perform an acoustic survey proving that new aircraft and propulsion designs can dramatically reduce the sound of the supersonic boom.
Secondly, airport noise regulations are becoming more strict after 2020, making it challenging for a supersonic aircraft with a relatively low-bypass turbofan engine to gain regulatory approval.
But NASAs tests last year appear to have found a new exhaust nozzle design that dramatically reduces the noise on the ground.
In Fiscal 2016, NASA plans to launch a series of ground tests of innovative concepts for integrated low-noise supersonic propulsion systems.
Several companies, including Aerion, Boeing, GE Aviation, Gulfstream, Lockheed Martin, Pratt & Whitney, Rolls Royce and United Technologies, are listed in NASA budget documents as cost-sharing partners on projects related to commercial supersonic technology.
Source: FlightGlobal.com
