Full-Scale A320 Landing Gear Airframe Noise Characteristics

Abstract

Flyover noise levels of today's aircraft in the approach configuration - i.e. with slats, flaps and gears deployed -are occasionally dominated by airframe noise contributions. Initial airframe noise tests were performed in the German-Dutch Wind Tunnel, employing full-scale A320 landing gears. Farfield noise characteristics were determined from measurements with different gear configurations (covering different gear elements with streamlined fairings) at wind speeds ranging from 40 to 78 m/s. Aerodynamic noise from landing gears turnes out to be broadband with constant levels in 1/3-oct. bands up to 3 kHz. Levels increase corresponding to the 6th power of flow velocity. From the results of this study it is expected that a noise reduction potential of up to 5 EPNdB could be realized through localized applications of streamlined fairings and/or flow spoilers.