There is a general lack of publications on the acoustical and related non-acoustical properties of nanofibrous media. This work attempts to contribute to this gap and to highlight problems associated with acoustic and related non-acoustic characterisation of these materials. The work, presumably for the first time, applies Biot- and Darcy-type mathematical models to explain the observed acoustical and related non-acoustical behaviours of the nanofibres. It identifies theoretical gaps related to the physical phenomena which can be responsible for the observed acoustical behaviours of nanofibrous membranes and it presents recommendations to fill these gaps. The novelty of this work is in the use of a robust theoretical model to explain the measured acoustical behaviour of thin nanofibrous membranes placed on a foam substrate. With this model the actual flow resistivity of nanofibers is estimated from acoustical data. It is demonstrated that a classical model for the flow resistivity of fibrous media does not work when the Knudsen number becomes greater than 0.02, i.e. then the diameter of nanofibres becomes comparable with the mean free path.

普遍缺乏有关纳米纤维介质的声学和相关非声学特性的出版物。这项工作试图弥补这一差距，并突出显示与这些材料的声学和相关非声学特性相关的问题。这项工作大概是第一次，它应用了Biot型和Darcy型数学模型来解释观察到的纳米纤维的声学和相关非声学行为。它确定了与物理现象有关的理论空缺，这些空缺可能是造成纳米纤维膜声学行为的原因，并提出了填补这些空缺的建议。这项工作的新颖之处在于使用了强大的理论模型来解释放置在泡沫基材上的纳米纤维薄膜的声学特性。使用该模型，可以从声学数据估算出纳米纤维的实际流动阻力。结果表明，当克努森数大于0.02时，纤维介质流动阻力的经典模型不起作用，即纳米纤维的直径与平均自由程相当。