Quantified noise characteristics of the aircraft with control devices

Abstract

Novel wing designs will incorporate advanced wing-tip devices for a quick wake-vortex break down and an increased wing performance through different devices, e.g. differential spoiler setting, large wing-lets, mini trailing edge devices and sub-boundary layer vortex generators. Advanced wing configurations will enhance the aircraft's capability to perform noise abatement flight procedures, but may also generate excess aerodynamic noise. Therefore farfield noise measurements were conducted in the open test section of the DNW-LLF on a 1/10.6 scaled X408D (A340) model for all relevant aircraft configurations, to quantify the different devices' noise characteristics. All devices were tested individually by means of an out-of-flow traversing microphone boom. In comparison of measured noise directivities with and without devices installed only small effects on noise in the order of 1 dB were detected.