Research On Fast Computation Of Acoustic Ropagation In Pekeris Waveguides

The perfectly matched layer (PML) is a tool used for truncating unbounded domain in numerical simulations of wave propagation in an unbounded region, then the unbounded domain is transformed into a bounded area. In this paper, for the bounded domain of two layers, the operator marching method is improved to other form through the technology of adjoint eigenoperator, which is called as the improved operator marching method(IOMM). The local base transform in IOMM needs to be done in each marching step,here we do this with the advantage of the weighted orthogonal property of conjugation operators that makes the IOMM becomes more fast and efficient.The technique of PML combines with IOMM to provide effective computation of a typical underwater acoustic propagation in Pekeris waveguides. Simulation numerical results show that the treatment is more feasible and effective. The full text is divided into five chapters.Chapter â…  introduces the background and the status of the research questions of Ocean acoustic waveguides in this dissertation. We summarize the purposes, contents and significance of this dissertation.In Chapter â…¡ we investigate the elementary equations and eigenvalue prob-lems with PML.The formulation of the improved operator marching method(IOMM) and the marching steps is shown in Chapter â…¢.In Chapter â…£ we give a testification of the methods we proposed above through numerical experiments.In Chapter â…¤ we summarize the full text and point out some further works.