The design of the system used for measuring radiated noise at anchor condition

With the development of quiet submarine technology, the radiated noise of targets has decreased a lot, and the environmental background noise of measuring machines is becoming larger and larger with the increase in number and tonnage of ships. Thus, the measuring targets will become more and more difficult. The test of radiated noise when a vessel is at anchor has very important significance for evaluating ship radiated noise and finding the main noise source. This paper presents the principle and the construction method of a kind of radiated noise testing system for vessels which are at anchor. The system uses the vector hydrophone as the wet end, and combined the single point measurement method and the array measurement method. In our experiment, we firstly, focus on different measurement sites such as the main fan, the lubricating oil pump and other mechanical components, and the vibration and radiated noise for those parts can be respectively measured. Next, we operate all mechanical parts simultaneously in order to measure the noise of the mechanics as a whole. Then the system can automatically analyze the main components of the noise and obtain the main noise source. Also, at the same time, the radiated noise measurement system applies basic technology, to collect the data and analyze the transmission path of radiated noise. The radiation noise of the target can be measured by this system whilst it is moored. Consequently, through the acquisition module, we can observe the waveform and real-time power spectrum of each signal channel, and can thereby calculate the target location. Through follow-up processing software, the target signal can be analyzed and calculated deeply, and the focus of the target can be obtained.