Properties of the Acoustic Vector Field near the Underwater Planar Cavity Baffle and Its Application

In order to apply the acoustic vector hydrophone on a ship, the properties of the acoustic vector field near the underwater planar cavity baffle are studied based on the Euler description and Lagrange description. The acoustic vector field is calculated based on the transfer matrices and matched boundary conditions. It is shown that the interference structure appears in the acoustic field. In particular, the particle velocity direction and intensity vector cannot directly reflect the azimuth of the source. The points at which the particle velocity is zero are saddle points and nodal points in the particle velocity vector field. Moreover, the particle motion is generally an ellipse near the planar cavity baffle. Furthermore, this paper defines a parameter that can fully represent the particle motion, and the direction of arrival (DOA) can be estimated using a single acoustic vector hydrophone using this parameter in some cases. At the end, the validity of the theoretical calculation and the method of using the parameter to estimate the DOA are verified experimentally.