Effect of phase transformations on acoustic wave reflection from contaminated fog boundary

Acoustic wave reflection from a vapor-gas medium is of great relevance. This is mainly due to natural phenomena, such as a layer of fog and dusty gas in the atmosphere and atmospheric clouds. It is also possible to use gas-droplet mixtures (fogs) to hide various objects, such as ships, from radars. In this paper the problem of sound waves propagation in a two-phase medium with liquid droplets and solid particles has been considered. A model, which allows determining the reflection coefficient from the gas-vapor medium boundary, has been presented. Based on the obtained results, the influence of the initial vapor concentration on the acoustic wave reflection has been analyzed. It has been shown that the dependence of the reflection coefficient on the volume content is monotonic in the case of normal incidence of the wave. In the case of oblique incidence of the wave, a nonmonotonic dependence is observed. The dependence of absorption of a sound wave by the propagation medium on the volume content of dispersed inclusions has been revealed for an oblique incidence of a sound wave on the interface between two media. The results of the calculations can be of interest in solving the problems of masking objects and acoustic sounding of the atmosphere.