Research On Sound Field Computation In The Ocean Environment With Elastic Bottom

It is now well accepted that the computational acoustic technique has made a significant contribution to the ocean acoustic community. Most existing underwater acoustic propagation models have been developed to provide solutions to problems involving water layer. The ocean is, however, surrounded by land and is bounded above by air and below by an elastic bottom. With this in mind, we have focused our attention on the fluid-elastic acoustic model. This work is still at an early development stage.The purpose of this thesis is developing a uniform propagation model in the ocean environment with fluid-solid interface, and handling of the horizontal fluid/elastic interface boundary. The required interface conditions, continuity of vertical components of displacement, continuity of vertical components of stress and that horizontal components of stress must vanish on the interface, are satisfied with this numerical treatment.In the thesis, a uniform style of parabolic equation has been derived by using methods of far-field approximation and parabolic approximation. The difference form of these parabolic equations which is unconditional stable have been gained by methods of ODE(ordinary difference equation)and finite difference, with the same method above we've got the difference form of the interface conditions which is also unconditional stable. We have computed the whole sound field in water and elastic media with use of computer. And a test of numerical solution to the parabolic in terms of potential field was computed. The test example is well consistent with the complete theoretical development, and that demonstrate our methods validity,.