Control of cavity acoustics by surface waviness in landing configurations

Abstract

The aviation industry’s interest towards cavity control methods rose accordingly due to the acoustic attenuation potential of such methods. However cost effective control devices which are also efficient over a wide range aircraft operations are yet to be developed. This paper investigates the use of a sinusoidal surface modification application upstream of a cavity as a passive acoustics control device in approach conditions. Optimum sinusoidal amplitude and frequency were previously determined by the means of a two-dimensional computational fluid dynamics analysis for a cavity with a length to depth ratio of 4. A complete three-dimensional CFD analysis of this configuration as well as a base-line case without control device was carried out in this study. The overall sound pressure level was reduced with the surface modification at the majority of the points investigated.