Three-dimensional wide-angle azimuthal PE solution to modified benchmark problems

Abstract

In predicting wave propagation, the size of the angle of propagation plays an important role; thus, the concept of wide angle is introduced. Most existing acoustic propagation prediction models do have the capability of treating the wide angle but the treatment, in practice, is vertical propagation angle. This is desirable for solving 2D (r–z) problems. Typically, 3D problems are dealt with an N by 2D approximation. To deal with problems possessing 3D effects, the azimuthal coupling terms have to be considered in PE approximation. Moreover, in extending the 2D treatment to 3D, the wide−angle capability is maintained in most 3D models, but it is still vertical. Hence, the concept of wide angle is introduced in the azimuthal direction to enhance the capability of predicting the azimuthal coupling and thus the 3D effects. A truncated wedge−shaped ocean which is modified from ASA benchmark problems is used in this study. The results show apparent 3D effects and validate the 3D wide−angle azimuthal PE model, a wide−angle version of FOR3D.