The Research Of The Digital Waveguide Networks For The Vector Sound Field

As the vector sensor can provide vector sound field information for the sonar performance improvement, it has been widely used in the underwater sound propagation and underwater acoustic engineering research. Up till now, most of the underwater sound propagation models are about the scale sound field. It is necessary to develop vector sound field model for underwater sound propagation research.In this thesis, the digital waveguide networks (DWN) method is applied in the research of vector sound field. The DWN is a new method based on the wave theory to model the sound field, which solve the wave equations as solve a circuit networks based on the analogy between the acoustic system and the electrical networks. The DWN treat the sound propagation as the scattering and propagation of wave variables in multiple-dimensions. The basic elements in a waveguide network are the bidirectional delay lines and the scattering junctions. The bidirectional delay lines carry energy from one part of the network to another, and the energy incident on a junction may be reflected.In this thesis, the vibrating systems of one dimension and two dimensions are simulated by DWN, and the results are compared with the analytic solutions. Then, the digital waveguide networks are used to calculate the transmission loss of a point source in a homogeneous ocean environment of two dimensions and three dimensions. The results are compared with the FFP method and image method. The consistency between the results of these methods shows that it is feasible to apply the digital waveguide networks in the underwater sound propagation model. But it should be noted that the computational complexity and memory requirements are two disadvantages for the DWN method. The dispersion error is also discussed and some suggestion for the further research work is given in this thesis.