Impacts of porous material fluid bulk properties on noise attenuation performance of cylinder shell structure based on finite element model

Abstract

SummaryThe noise control method of laying acoustic blanket is adopted to construct a cylinder cell noise experimental device; a typical porous material, melamine foam (MF), is used for noise attenuation experiments in aluminum (Al) and aluminum/melamine foam (Al/MF) cylinder shells and to achieve corresponding in‐shell noise response spectrograms. Based on the Virtual Lab acoustics software, a finite element model has established for the analysis of noise in the Al/MF cylinder shell and numerical simulation computation has been conducted for the acoustic mode and in‐shell acoustic response; the correctness of the finite element model is verified via comparison with theoretical and measured data. On this basis, the impacts of porous material fluid bulk properties on the noise attenuation effect of the Al/MF cylinder shell are further studied within the frequency range of 0 ∼ 1000 Hz. It is suggested that fluid bulk properties changes pose relatively high impacts on internal noise response of a cylindrical cavity. Within low‐frequency and high‐frequency ranges, the response value of sound pressure increases with flow resistivity, while the response value of sound pressure decreases with the increases of tortuosity, porosity, flow resistivity (only for the medium frequency range), and viscous characteristic length in the medium and high frequencies ranges.