Airframe Noise — Generation and Reduction

The proposed increase in stringency of the ICAO Chapter-3 noise certification limits and other operational restrictions due to noise necessitates the development of source noise reduction technologies for subsonic commercial aeroplanes. The noise from such aeroplanes during approach is largely dominated by airframe noise, i.e. the noise generated by the interaction of flow and those aircraft components deployed for landing, such as the landing gears and the wing high-lift devices. This paper will present highlights from recent DLR research projects, indicating the source noise reduction potential of design changes on landing gears and on wing high lift devices which could be employed without hampering the basic functionality of such components.