Study On Measurement Method And Characteristic Of Flow Noise In Seawater Pipes

The flow-noise in seawater pipeline has more influence on working environment and warship personnel health, and radiation noise from the pipeline exits also seriously effects on the hiding ability of warships. This paper studies the mechanism generated from flow-noise in seawater pipeline, introduces controlling method of flow-noise, analyzes sound field characteristics of flow-noise in seawater pipeline system and the merits and demerits of measuring the flow-noise methods in and out of the pipeline. In our experiment, a test measuring device of seawater muffler is used in a measuring chamberlet to verify that a method of reverberation chamberlet is difficult to exactly measure the low frequency flow-noise in pipeline. At the same time the insertion lose of water muffler in the low frequency was measured by the measuring chamberlet method . In order to analyze the fluid dynamic characteristic in seawater pipeline system, the test device of fluid dynamic characteristic in seawater pipeline system is set up . In this experiment, the velocity of pressure wave propagation is measured by frequency analysis technique and the measured result is reliable. According to the frequency analysis technique and a basic theory of linear transfer matrix, the pulsation pressure value in pipeline is predicted by the measured values from four pressure transducers. And it is found that the test results are identical with theoretical calculation. This paper analyzes the influence of the test device cycling characteristic for fluid dynamic characteristic on the pulsation pressure measurement in seawater pipeline system.