The Research On The Identification Technique Of Complex Structure Sound Source In Semi-space

In order to control and reduce the radiated noise of underwater structure more effectively, it is very important to identify the main noise sources. For the conventional methods for noise sources identification can hardly be used in precisely analyzing the complex noise sources of underwater structures, the sound source identification technology based on the near field acoustic holography (NAH) theory has been carried out in this thesis.At present, however, most of the research is focused on the simple source noise in the full space (free acoustic field).In engineering application, most of the noise sources come from the complex structures set in semi-space, and the properties of the radiated sound field can't be exactly predicted by the technology of full space acoustic holography. Therefore, the research on the acoustic field reconstruction in semi-space is very important for its use in practical conditions.This method described here has been verified by numerical simulation. There are three kinds of sound source in this paper, including a rectangle steel plate, a steel cylindrical shell and a steel spherical shell excited by point forces. The results show that it's an efficiency way to deal with the problem of sound source identification in semi-space.