Open and closed tube method for determination of resonance frequencies of nanofibrous membrane

Nanofibrous layer performs as a membrane that vibrates at low frequencies. This property is obtained by nano dimensions of the interfiber areas. Sound waves incident on the acoustic resonance membrane make the membrane oscillate, and the maximum amplitude occurs in the case of resonance. The structures based on the nanofibrous layers are employed for low-frequency sound absorption. The resonance of the nanofibrous elements allows acoustic energy to be converted into thermal energy. In this article, a nanofibrous layer was produced by electrostatic spinning from an aqueous solution of polyvinyl alcohol and the resonance effect of nanofibrous layer was studied. For this purpose, the new method developed for determination of resonance frequencies of a membrane was employed. The ultimate objective of the study was to assess the effect of mass per unit area on resonance frequencies of the membrane placed in an open and closed tube. The results indicated that the resonance frequencies of the membrane decreased with an increase of the mass per unit area of the nanofibrous membrane. Except for the lowest frequencies (first resonance peak), the resonant behavior of the membrane was affected by the resonance of tube.