Characterization of Low Noise Technologies Applied to a Full Scale Fuselage Mounted Nose Landing Gear

Abstract

The negative impact of aircraft noise includes effects on population’s health, land use planning and economic issues such as building restrictions and operating restrictions for airports. Thus, the reduction of noise generated by aircraft at take-off and approach is an essential consideration in the development of new commercial aircraft. Among the different aircraft noise sources, landing gear noise is one of the most significant during approach. This research presents results from the European Clean Sky funded ALLEGRA project, which investigated a full-scale Nose Landing Gear (NLG) model featuring the belly fuselage, bay cavity and hydraulic dressing. Tests were performed for a variety of wind speeds and yaw angles. In this paper, a characterization of the noise generated by the full-scale Nose Landing Gear (NLG) model is presented and the different techniques used for characterizing acoustic sources on the NLG are described. The landing gear noise source is characterized in terms of OASPL, directivity, source spectra, PNL and PNLT. A comparison between the NLG with and without the application of low noise technology is presented.