Different radiation impedance models for finite porous absorbers
Regular paper
Acoustic Technology Group, Technical University of Denmark
Monday 1 june, 2015, 14:40 - 15:00
0.9 Athens (118)
Abstract:
The statistical incidence absorption coefficient of finite absorbers is measured in a reverberation chamber
according to the international standard ISO 354 and is referred to as Sabine absorption coefficient. Sabine
absorption coefficient
varies with the specimen size mainly due to diffraction evoked by the specimen edges. When predicting the
Sabine absorption coefficients of porous samples, one can incorporate radiation impedance models for
finite absorbers. In this study, different radiation impedance models are compared when predicting Sabine
absorption coefficients, and experimentally validated for several porous samples. Among them,
Thomasson's original model and the size corrected transfer matrix method suggested by Rhazi et al. are
compared. Thomasson's correction seems to be the most accurate model
in terms of estimation of the statistical absorption coefficient for finite porous materials.