Parametric study of the influence of compression on the acoustical absorption coefficient of automotive felts

The present note describes some work related to the modelization of acousti cal absorption properties of compressed porous materials. An 'equivalent fl uid' model with five parameters is used. This prediction technique is valid ated with some industrial materials being 1-D compressed along their thickn ess, starting from a felt mat having a given basic weight. The obtained res ults tend to indicate that an adequate prediction of the decrease in the co efficient of absorption is possible with this method. (C) 2001 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.