Interior Noise and Sound Transmission

Abstract

AbstractAircraft interior noise control as a major factor of cabin and cockpit comfort is considered as an essential design requirement by transport airplane manufacturers. External sources such as the turbulent boundary layer excitation and acoustic radiation from engines being the main interior noise contributors over a large frequency range, this section focuses mainly on sound transmission through fuselage structure and noise control treatments. After describing the existing noise sources and the main characteristics of a fuselage structure including classical noise control treatments, the emphasis will be put on the methodology to assess interior noise, based on typical testing and existing modeling methods. The complexity of the fluid‐structure coupled issue and the main weak and strong points of each modeling method, both at aircraft and fuselage element level, will be addressed. Then, understanding and modeling the vibroacoustic behavior of stiffened structures being necessary to assess overall interior noise level, a dedicated section will describe the main phenomena governing sound transmission through these elements. Finally, the excitation field effect on sound transmission mechanisms and particularly on noise control treatments efficiency will be discussed. Turbulent boundary layer, diffuse sound field, and structure‐borne excitation will be considered.