Airframe noise experiments in DLR's project "Quiet Air Traffic"

Abstract

Todays low-noise high-bypass-ratio engines have made airframe noise for large commercial aircraft in the approach configuration comparable to engine noise. As a consequence, flow noise from landing gears and from high lift devices on wings - and its control - will become ever more important. Within DLR's interdisciplinary project "Quiet Air Traffic" therefore an experimental airframe noise study was performed, comprising parametric wind tunnel experiments on full scale landing gears, scaled wing sections, on complete scale model aircraft and on a full scale A320 wing-section. Tests were performed in the Aeroacoustic Wind Tunnel Braunschweig (AWB) and in the German-Dutch Wind Tunnel (DNW-LLF). The results led to the identification of major airframe noise sources and the development of both noise reduction concepts and prediction schemes. This study revealed an airframe noise reduction potential on the order of 3 dB for todays aircraft configurations.