A Study of Acoustic Modes as a Source of Airframe Cavity Noise

Under certain conditions, flow excited cavities can generate large pressure fluctuations, undesirable noise and significant structural loads. This project is an experimental study of noise emissions of a cylindrical Helmholtz resonance with a high H/D ratio. These harmful sounds are becoming more and more of a concern in societies because they impact the value of the residential areas surrounding the airports and the health of their inhabitants. This master thesis provide a better understanding of acoustic modes and Helmholtz resonance and how they react when confronted to attenuation technics such as a mesh, a foam and a honeycomb liner.