Comments on the limp frame equivalent fluid model for porous media

In this letter, the low and high frequency limits of the effective density characterizing a limp frame porous medium are investigated. These theoretical limits are compared to the ones found for a classical rigid frame porous,medium, and to experimental measurements. While the high frequency asymptotic behaviors of both limp and rigid effective densities are usually only slightly different, their low frequency behaviors are significantly different. Compared to experimental measurements performed on a limp frame fibrous layer, only the limp frame effective density yields good correlations over the whole frequency range. (c) 2007 Acoustical Society of America

在这封信中，对表征软质框架多孔介质的有效密度的低频和高频极限进行了研究。将这些理论极限与经典刚性框架多孔介质的理论极限以及实验测量结果进行了比较。虽然软质和刚性有效密度的高频渐近行为通常仅有微小差异，但它们的低频行为却有显著不同。与在软质框架纤维层上进行的实验测量相比，只有软质框架有效密度在整个频率范围内呈现出良好的相关性。（c）2007美国声学学会