Structural design and analysis of thin broadband absorber with built-in resonator
Micro-perforated panel(MPP)sound absorber has a wider absorption band compared to Helmholtz resonator(HR),but its low-frequency sound absorption implementation requires a larger air back cavity,it is difficult to apply in space-limited environments.A thin type of noise reduction sound absorber that combines MPP with HR(MPPHR)is designed in this paper,which not only improves the low-frequency sound absorption performance,but also has the advantages of wide-band sound absorption of MPP.Firstly,based on the theory of MPP and Helmholtz resonator,the equivalent circuit model is established and the acoustic impedance of the structure is calculated.Then,the MPPHR sound absorption characteristics were analyzed by finite elements method.Finally,the acoustic impedance model and the finite element simulation results of MPPHR were verified through experiments.The results show that the MPPHR absorber has a wider absorption band.The MPPHR with a thickness of 30 mm have a half absorption band of up to 1294 Hz,which is nearly 500 Hz wider than the equal thickness MPP.In addition,the MPPHR has better low-frequency absorption efficiency.
Micro-perforated panelHelmholtz resonatorBroadband frequency sound absorption
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维普
