Fictitious domain method for acoustic waves through a granular suspension of movable rigid spheres

David Imbert (1, 2) , Sean Mcnamara (1) , Yves Le Gonidec (2)

1 IPR - Institut de Physique de Rennes
2 GR - Géosciences Rennes

We develop a model to couple acoustic waves and the motion of rigid movable grains in a submerged suspension. To do so, we use the fictitious domain method based on distributed Lagrange multipliers to enforce the natural jump condition of the wave equation and a rigidity constraint. One can then model the granular medium with “Molecular Dynamics” or related methods. Both dynamic and acoustic numerical results are compared with analytic solutions of acoustics and an estimation of the error is given. We show energy transfers between two submerged grains separated by water and linked to their own spring while oscillating. The model is applied at large scale with a suspension of many grains to foresee its future possibilities.

Mots clés: Suspension; Fictitious domain method; Granular medium; Distributed Lagrange multipliers; Movable rigid grains; Acoustic wave equation

Domaines: Sciences de la Terre; Physique [physics]

David Imbert, Sean Mcnamara, Yves Le Gonidec. Fictitious domain method for acoustic waves through a granular suspension of movable rigid spheres. Journal of Computational Physics, 2015, 280, pp.676-691. ⟨10.1016/j.jcp.2014.10.006⟩. ⟨insu-01100866⟩