Influence of bubble size and thermal dissipation on compressive wave attenuation in liquid foams
Institut de Physique de Rennes, UMR 6251 CNRS/Université de Rennes 1 - Rennes, France
Received: 24 June 2015
Accepted: 20 October 2015
Acoustic or blast wave absorption by liquid foams is especially efficient and bubble size or liquid fraction optimization is an important challenge in this context. A resonant behavior of foams has recently been observed, but the main local dissipative process is still unknown. In this paper, we evidence the thermal origin of the dissipation, with an optimal bubble size close to the thermal boundary layer thickness. Using a shock tube, we produce typical pressure variation at time scales of the order of the millisecond, which propagates in the foam in linear and slightly nonlinear regimes.
PACS: 47.57.Bc – Foams and emulsions / 43.25.Ed – Effect of nonlinearity on velocity and attenuation
© EPLA, 2015