The reduction of noise generated by aircraft at take-off andapproach is crucial in the design of new commercial aircraft.Landing gear noise is significant contribution to the total noisesources during approach. The noise is generated by theinteraction between the non-aerodynamic components of thelanding gear and the flow, which leads to turbulence generatednoise. This research presents results from the European CleanSky funded ALLEGRA project. The project investigated a fullscaleNose Landing Gear (NLG) model featuring the bellyfuselage, bay cavity and hydraulic dressing. A number of lownoise treatments were applied to the NLG model including aramp door spoiler, a wheel axel wind shield, wheel hub capsand perforated fairings. Over 250 far field sensors weredeployed in a number of microphone arrays. Since technologieswere tested both in isolation and in combination the additiveeffects of the technologies can be assessed. This study describesthe different techniques used to quantify the contribution ofeach technology to the global noise reduction. The noisereduction technologies will be assessed as a function offrequency range and through beamforming techniques such assource deletion.
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