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

摘要

The noise control method of laying acoustic blanket is adopted to construct a cylinder cell noiseexperimental device; a typical porous material, melamine foam (MF), is used for noise attenuationexperiments inaluminum(Al)andaluminum/melaminefoam(Al/MF) cylinder shellsandtoachievecorresponding in-shell noise response spectrograms. Based on theVirtual Lab acoustics software,a finite element model has established for the analysis of noise in the Al/MF cylinder shell andnumerical simulation computationhasbeenconducted for the acousticmodeandin-shell acousticresponse; the correctness of the finite elementmodel is verified via comparison with theoreticaland measured data.Onthis basis, the impacts of porous material fluid bulk properties on the noiseattenuation effect of the Al/MF cylinder shell are further studied within the frequency range of0 ∼ 1000 Hz. It is suggested that fluid bulk properties changes pose relatively high impacts oninternal 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 ofsound pressure decreases with the increases of tortuosity, porosity, flow resistivity (only for themedium frequency range), and viscous characteristic length in the medium and high frequenciesranges.