Research On Numerical Prediction Of Acoustic Field In Shallow Water Based On Acoustic Ray Theory

In the study of underwater acoustics, the data in the acoustic field can be got not only by experiment, but also by computer simulation which is an important way. We called this way "numerical prediction of acoustic field", which is one of the most basic subjects in underwater acoustic. Based on available underwater acoustic propagation theory, it builds a model closed on real sea environment and computes the acoustic field.The main content of this dissertation is researching the numerical prediction of acoustic field in shallow water especially in layered shallow water using acoustic ray theory and using the outcome of the numerical prediction to study some acoustic propagation laws. The numerical prediction of acoustic field in uniform shallow water can be completed by virtual source formula. But the numerical prediction of acoustic field in layered shallow water needs to start from the computation of eigenrays. The acoustic intension of some place in shallow water is the sum of several eigenrays. This dissertation mainly researched a way to rapidly compute the eigenrays in layered shallow water, and built up a method to predicting the acoustic field in uniform shallow water and layered shallow water. Using this method, the numerical prediction of acoustic field in uniform shallow water and layered shallow water of one lay, two lays and three lays was respectively researched in this dissertation. The prediction results fit with the common laws of sound propagation in shallow water, and were proved by the experiment. The researching achievement is significant to the research of acoustic propagation and acoustic flied prediction in shallow water.