External Aircraft Noise Reduction Liners

NASA Langley Research Center, in collaboration with Boeing and Lockheed Martin, has developed a new external acoustic liner for aircraft noise reduction. While the acoustic liner can be placed on any external aircraft surface, one attractive application is for open-rotor noise reduction. Airframe manufacturers are considering open rotor engines for future aircraft designs as they provide significant fuel savings. However, open rotor engines have no nacelle and thus, do not allow the use of conventional nacelle liners for noise abatement. This technology strategically places acoustic liners on the external surface of the aircraft to reduce such engine noise.