Finite element modeling of thermoviscous acoustics in closed cavities

Nicolas Joly (1)

1 LAUM - Laboratoire d'Acoustique de l'Université du Mans

A numerical methodology is presented to compute the acoustic field in a closed domain filled by a thermoviscous fluid, using the finite element method. The formulation based upon temperature variation and particle velocity is well suited for both (i) modeling the acoustic, thermal and viscous effects in the fluid bulk and (ii) accounting for the non-slip and the thermal boundary conditions on the solid. Due to the development of thin thermal- and viscous- boundary layers compared to the acoustic wavelength, very different scales are present in the field. The finite element mesh used is iteratively adapted to account for these different scales, and anisotropic because of boundary layers effects. Results are presented for the axisymmetrical back chamber of a miniature condenser microphone.

Mots clés: thermoviscous acoustics; finite element; acoustic boundary layers; diffusion; microphone

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]

Nicolas Joly. Finite element modeling of thermoviscous acoustics in closed cavities. Acoustics'08 Paris, Jun 2008, Paris, France. pp.2469-2474. ⟨hal-00346938⟩