title: Influence of sorption on sound propagation in granular activated carbon.
abstract: Granular activated carbon (GAC) has numerous applications due to its ability to adsorb and desorb gas molecules. Recently, it has been shown to exhibit unusually high low frequency sound absorption. This behavior is determined by both the multi-scale nature of the material, i.e., the existence of three scales of heterogeneities, and physical processes specific to micro- and nanometer-size pores, i.e., rarefaction and sorption effects. To account for these processes a model for sound propagation in GAC is developed in this work. A methodology for characterizing GAC which includes optical granulometry, flow resistivity measurements, and the derivation of the inner-particle model parameters from acoustical and non-acoustical measurements is also presented. The model agrees with measurements of normal incidence surface impedance and sound absorption coefficient on three different GAC samples.
authors: Carbon Air Ltd., The Innovation Forum, 51 Frederick Road, Salford M6 6FP, England.
authors: Rodolfo
authors: R
authors: Venegas
authors: Acoustics Research Centre, University of Salford, Salford M5 4WT, England.
authors: Olga
authors: O
authors: Umnova