University researchers have developed a method to achieve significant noise reduction with simple modifications of the engine exhaust. These modifications have a very small effect on engine thrust. Moreover, the nature of the modification allows for on-demand activation of the noise suppression mechanism when quiet operation is desired; e.g, during takeoff and landing. At other flight stages such as cruise, the mechanism could be deactivated. This results in a very efficient noise suppression system.
This invention impacts engines for both subsonic and supersonic aircraft, can be retrofitted onto existing engines, or could be an integral design feature of new powerplants. University experiments for flyover noise predictions simulating the exhaust conditions of an engine similar to the Pratt & Whitney JT8D-209 showed a reduction of the effective perceived noise level (EPNL) by 5.0 to 6.3 decibels.
|United States Of America||Issued Patent||8,997,454||04/07/2015||2002-324|
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