Air Curtains as Flow Control Low Noise Technologies for Landing Gear Noise Reduction

This paper examines the use of different air curtain nozzles to reduce the aerodynamic noise radiated from a modified LAGOON landing gear, as tested in the EU funded H2020 collaborative research project: INVENTOR, InnoVative dEsign of iNstalled airframe componenTs for aircraft nOise Reduction. At approach to landing, landing gear noise is still a significant contributor to environmental noise in the vicinity of airports. Progress is being made with ambitious projects which aim to develop significantly reconfigured aircraft architectures to reduce airframe noise. The current project examines a noise abatement concept which could be retrofit to existing landing gear configurations as an interim measure or as part of a longer term solution. Flow control in the form of low TRL "air curtains" which form a fluidic shield, or virtual fairing, are examined. In order to provide a simplified baseline landing gear mock-up on which to test the low noise nozzles, the LAGOON NLG is modified with the addition of a torque-link and brakes and is called the ``LAGOON-SLG''. The air curtains are examined in DLRs AWB aeroacoustic facility in Braunschweig, Germany.