London, July 1 : That shrieking aircraft noise of jet engines during take off and landing is one of the biggest problems faced by the aviation industry. A researcher now claims that it is possible to quieten a jet engine by separating its exhaust into high and low speed flows.
Dimitri Papamoschou at the University of California, Irvine, US, said that most of the noise in the engine is caused by the turbulence in the fastest-flowing air.
And they can direct the noise upwards by separating the air into two channels of different speeds away from the ground and its inhabitants.
Papamoschou found that in NASA created simulations, this technique could successfully reduce the amount of noise coming to the ground by more than 6 decibels.
And as we know that decibels are a logarithmic scale, this is a considerable amount, so that every drop of 3 decibels would equal to a halving of power.
A "silenced" engine would produce about a quarter of the acoustic energy of a conventional one and be significantly quieter.