{ "id": "1110.3438", "version": "v1", "published": "2011-10-15T20:19:27.000Z", "updated": "2011-10-15T20:19:27.000Z", "title": "A Finite Difference method for the Wide-Angle `Parabolic' equation in a waveguide with downsloping bottom", "authors": [ "D. C. Antonopoulou", "V. A. Dougalis", "G. E. Zouraris" ], "comment": "2 figurew", "categories": [ "math.NA" ], "abstract": "We consider the third-order wide-angle `parabolic' equation of underwater acoustics in a cylindrically symmetric fluid medium over a bottom of range-dependent bathymetry. It is known that the initial-boundary-value problem for this equation may not be well posed in the case of (smooth) bottom profiles of arbitrary shape if it is just posed e.g. with a homogeneous Dirichlet bottom boundary condition. In this paper we concentrate on downsloping bottom profiles and propose an additional boundary condition that yields a well posed problem, in fact making it $L^2$-conservative in the case of appropriate real parameters. We solve the problem numerically by a Crank-Nicolson-type finite difference scheme, which is proved to be unconditionally stable and second-order accurate, and simulates accurately realistic underwater acoustic problems.", "revisions": [ { "version": "v1", "updated": "2011-10-15T20:19:27.000Z" } ], "analyses": { "subjects": [ "65M06", "65M12", "65M15", "76Q05" ], "keywords": [ "finite difference method", "wide-angle", "accurately realistic underwater acoustic problems", "simulates accurately realistic underwater acoustic", "crank-nicolson-type finite difference scheme" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1110.3438A" } } }