Nonlinear acoustic dissipation mechanism of a slit resonator

To simulate the vortex/sound interaction phenomenon at a slit with high sound pressure level and calculate the acoustic impedance of the slit, a discrete vortex model was set up. By combining the discrete vortex model with a one-dimensional sound propagation model, the acoustic impedance and the absorption coefficient of the slit resonator were calculated. The numerical results reveal that the acoustic properties of the slit are dominated by the vortex shedding and the evolution of the vortex sheet; the absorption coefficient of the resonator increases with the increase of the sound pressure level; the frequency of the incident sound has significant influence on the absorption coefficient of the resonator. The present results agree well with the previous direct numerical simulation (DNS) results.