The Challenge To Break The Ultimate Noise Barrier: Sources and Control of Airframe Noise

Abstract

The expected increase in stringency of the ICAO Chapter-3 noise certification limits necessitates the development of source noise reduction technologies for future subsonic commerical aeroplanes entering the market in the next two decades. The noise from such aeroplanes during landing approach is dominated by airframe noise, i.e. the noise generated by the interaction of flow and aircraft components deployed for landing, such as landing gears and wing high-lift devices. This paper discusses highlights from recent appropriate national and European research projects which were initiated to further the understanding of the underlying aeroacoustic source mechanisms through wind tunnel tests employing full-scale landing gears and a full-scale wing and to demonstrate the potential of yielding up to 3 dB noise reduction in the farfield by means of technically feasible design changes on these aircraft components.