Frequency variability of the vertical profile of the first normal mode of pressure and particle velocity in a shallow water waveguide

Abstract

Frequency variability of the vertical profile of the first normal mode of pressure and particle velocity in a shallow water waveguide

Lisyutin V.A., Lastovenko O.R, Rybakova K.A., Luchin V.L., Petrenko N.V., Yaroshenko A.A.

Incoming article date: 02.07.2021

The article is devoted to the analysis of the vertical structure of the acoustic pressure field and the first-mode particle velocity in a hydroacoustic waveguide in shallow water. A waveguide consisting of a water layer with a constant sound velocity profile, a transition layer, and a half-space is considered. The acoustic properties of the transition layer are assumed to be frequency dependent. Formulas are derived that describe the vertical profile of the normal mode of a particle velocity. The transformation of the vertical profile of the first mode with increasing frequency is analyzed. The phase difference relations between the normal mode of acoustic pressure and particle velocity are analyzed. A relationship is established between the change in the vertical structure of the normal modes of pressure and particle velocity and the acoustic properties of the transition layer.

Keywords: normal modes, particle velocity, seabed, attenuation coefficient