Acoustic propagation in a shallow water duct with large obstructions.

The characteristics of shallow water harbor or mooring environments present unique challenges to an acoustic propagation modeler. Established acoustic propagation codes were developed to address problems in deep water or more open shallow water environments where spherical or cylindrical geometries and one‐way propagation approximations can easily be employed. In shallow harbors, large structures, including pier pilings and deep‐draft vessels, that represent a significant blockage of the water‐column propagation path may need to be accounted for. It is of interest to predict the received levels of the acoustic field transmitted past these obstructions. In order to more easily and accurately represent the complicated geometry of the boundary conditions encountered in this environment, a finite element model (COMSOL) is used. Using this model, predictions of the impact on low‐frequency acoustic propagation by structures typically encountered in a harbor are made.