One-dimensional acoustic waves in air/water mixtures

Homogenisation theory is used to derive Wood’s formula for the speed at which a pressure wave can propagate in an air/water mixture. The smallness of the impedance ratio between air and water results in a dramatic lowering of the wave speed of the mixture and, when the air fraction is small, the pos...

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Detalles Bibliográficos
Main Authors: Farmer, CL, Ockendon, H, Ockendon, JR
Formato: Journal article
Idioma:English
Publicado: Elsevier 2021
Descripción
Summary:Homogenisation theory is used to derive Wood’s formula for the speed at which a pressure wave can propagate in an air/water mixture. The smallness of the impedance ratio between air and water results in a dramatic lowering of the wave speed of the mixture and, when the air fraction is small, the possibility of regions of persistent ringing in the vicinity of the boundary where the pressure is applied. Only Goupillaud media are considered and, for the periodic case, the asymptotic predictions are validated against exact numerical calculations. An example in which the air/water layers vary randomly is also presented.