Transmission loss of multilayer panels containing a fluid using progressive wave model: Comparison with impedance progressive model and experiments

Abstract

The progressive wave model is applied to calculate transmission loss (TL) of triple layer panels. Theoretical values are then compared with impedance progressive model and experimental results. The triple layer panel comprises two solid layers with a middle layer of air or liquid. An impedance tube is employed to measure the TL values experimentally. The comparison of the two analytical models shows that the results of both models are relatively close. However, the progressive wave model leads to slightly larger values for a wide range of frequencies. Also, for the case of an air middle layer, a shift of the resonances to higher frequencies is observed in the results of the progressive wave model. Computational results also demonstrate that applying a liquid middle layer (replacing air) significantly improves the performance of the acoustic panel particularly at frequencies below 4000 rad/s (640 Hz). Shifting resonance frequencies to higher frequencies is another advantage of incorporating the liquid layer. Good agreement was also found between theoretical and experimental results. To cite this article: N. Mohammadi, M.J. Mahjoob, C. R. Mecanique 337 (2009).