Smart Active Lining Modules - Technology for Acoustic Comfort in Future Aircraft

Abstract

Acoustic comfort is an important issue in aircraft industry. Important external noise sources are the turbulent boundary layer (TBL) and the engines (jet or rotor). The induced aerodynamic and acoustic pressure fluctuations propagate as structure- and airborne sound through the fuselage into the cabin. The degree of sound transmission and with it the level of interior noise, strongly depends on the sound insulation of the primary fuselage structure and the interior lining elements. The increasing use of lightweight materials in aircraft industry such as carbon fiber reinforced plastics (CFRP) fuselage structures induces great acoustic challenges, which can not be solved solely by means of passive acoustic insulation. Active structural acoustic control (ASAC) is especially effective in the low-frequency domain (< 1kHz), where the sound transmission loss of passive structures is very low. The proposed smart active lining module uses ASAC technology to resolve the conflict between lightweight construction and acoustic comfort.