Characteristics and calculation method of sound radiation of cylindrical shell with porous sound-absorbing material under acoustic excitation

Abstract

ObjectiveThis paper aims to study the characteristics and calculation method of the vibration and sound radiation of single ring-stiffened cylindrical shells with porous fiber composite materials installed in the inner wall under acoustic excitation. MethodBased on the equivalent fluid theory model of Johnson–Champoux–Allard (JCA) and the transfer matrix of the multilayer medium, a theoretical formula of the sound absorption coefficient of multilayer sound absorption structures is derived. The three methods for calculating the vibration and sound radiation of a single ring-stiffened cylindrical shell with porous fiber materials under acoustic excitation, namely acoustic solid modeling of porous media, finite element model combined with theoretical formula and imposition of impedance boundary on sound absorption coefficient, are then verified and compared. Finally, the influences of sound-absorbing material's thickness, backed-air gap, static flow resistance, and material arrangement order on the acoustic absorption performance of the cylindrical shell are investigated. ResultsThe results show that laying porous fiber composite materials on the cylindrical shell internally can reduce the vibration and acoustic radiation of cylindrical shell structure. The sound absorption coefficient curve can quickly and effectively predict the resulting trend of the vibration and sound radiation of the cylindrical shell. ConclusionThe acoustic absorption performance of sound absorption structures can be effectively improved through the rational design of their properties and arrangement order of the sound-absorbing materials in order to achieve the purpose of vibration and noise reduction.

Keywords

• porous sound-absorbing material
• multilayer sound absorption structure
• sound absorption coefficient
• radiated noise