Kim Pham (Institut des Sciences de la Mécanique et Applications Industrielles, ENSTA, Palaiseau). Effective behavior of an array of Helmholtz resonators in the time domain.

We study the interaction of acoustic waves with a periodic array of Helmholtz resonators. This is done owing to an effective model derived from an asymptotic homogenization procedure in the time domain. Variational bounds are derived to show the well-posedness of the effective energy. Explicit expressions of the reflection and transmission coefficients are provided. Application of the effective model to design perfect absorbing wall is shown.