Supersonic and super-silent


From the past to the future - clic

By Victor Garcia, published on 05/18/2018 at 17:30 , updated at 17:58 L'express (electronic version)

NASA has signed a €207 million contract with Lockheed Martin to design a supersonic and super-quiet aircraft prototype.

Excerpt :
"Building the prototype will be a huge challenge
"In 1973, noise and the environment had been invoked by the United States - imitated by many countries - to ban supersonic flights, but it was above all a political decision to kill the Concorde, says Daniel Juvé, a researcher at the CNRS in acoustics and professor at the Ecole Centrale de Lyon. The Americans have shot themselves in the foot, because if they want to reopen this promising market, they will have to find a way to lift this ban." To develop new regulations, they will have to prove that supersonic aircraft can fly over their territory without inconveniencing people.
"Our partnership with NASA is a step in this direction," confirms Peter Losifidis, the engineer in charge of designing the prototype at Lockheed Martin. We are building the demonstrator, NASA will conduct tests over cities to assess noise pollution, and it will be up to the regulatory authorities to give the green light."
To measure the impact of noise, NASA will use the PLdB metric, a unit of measurement that reproduces the level of perceived annoyance on a scale similar to that of decibels. "But is it really the most appropriate measure to evaluate the nuisance?" asks Daniel Juvé. The Americans believe that yes, the Europeans doubt it." Population testing should provide a first response.

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