Nonlinear impedance modeling of resonator with high intensity incident acoustic wave

Abstract

The characteristics of acoustic liners can be expressed by acoustic impedance and an acoustic liner with good sound absorption performance relies on impedance model. In this work, a combined numerical and theoretical study is conducted, trying to take a deep observation of nonlinear absorption characteristics and nonlinear impedance modeling of microslit resonator under high incident acoustic intensity. Through the analysis of flow field data, an exponential relationship between normal velocity at the opening and the reactance is established, which is able to further improve the nonlinear resistance model introduced by high SPL that proposed by Ingard and Ising in 1960s. Furthermore, a complete nonlinear impedance model for multi slits or orifices is formed through the corporation with the linear impedance model by Maa and the grazing flow effects of Guess’s impedance model. Validation results against experimental data show that the proposed model could give a good prediction of nonlinear impedance of micro-resonators with multi slits or orifices under high SPL and in the presence of grazing flow.