Viscosity, surface tension and gravity effects on acoustic reflection and refraction

Abstract

The idea of the present work is to study from a unifying viewpoint the effects of viscosity, surface tension and gravity on acoustic reflection and refraction at a fluid interface, with the focus on modifications of Snell’s (Snell–Descartes’) law. While all these effects can be treated individually due to separation of the associated time scales, the contributions of surface tension to the gravity and viscosity cases are considered as well. The analysis reveals a number of phenomena among which are dispersive refraction laws, surface tension enhancing reflection, acoustic field generating vorticity at the interface, and viscosity enhancing/suppressing reflection as well as giving rise to extra reflected and transmitted waves.