Location And Identification Of Underwater Moving Noise Source Based On Statistically Optimal Near-field Acoustical Holography

Location and identification of underwater noise source is the primary task of noise and vibration reduction. Near-field acoustical holography technology can be used for recording radiated acoustic field and vibration mode of vibrating object effectively, and reconstruction results are not bound by Rayleigh criterion—which avoids the impact of vibrating frequency for reconstruction resolution. Statistically optimal Near-field acoustic holography can inhibit the interference of sound source outside measuring surface coverage for reconstruction result. The combination of vector array measurement techniques and statistically optimal algorithm can calculate sound pressure and particle velocity jointly—which improves the applicability of complex measurement environment.In this paper, the theory and experiment of location and identification for sports noise source based on statistically optimal near-field acoustical holography are studied.Firstly, the reconstruction formula of statistically optimal algorithm is derived, the main parameters selection of this algorithm is discussed, and this algorithm is proved by simulation. Simulation shows that this algorithm as a Patch method has great advantage when applying on large sound source plane reconstruction.Secondly, sound pressure and particle velocity jointly processing algorithm is simulated. The simulation result shows that sound pressure and particle velocity jointly processing algorithm can effectively inhibit sound source interference on the other side of measuring surface and improve reconstruction accuracy.Additionally, the model of moving source near-field acoustical holography measuring system based on vector array is established. This model can reduce implementation difficulty of NAH measuring. Simulation shows that the location of sound source can be predicted accurately and the sound field distribution of reconstruction surface can be calculated rightly by using statistically optimal method for moving sound source.At last, experiments for location and identification for moving standard sound source (single and double sound sources) are carried on. After processing and analysis of the experiments, the results show that statistically optimal near-field acoustic holography can accurately predict sound source position and effectively calculate distribution of sound field on reconstruction surface when applying to underwater moving sound source.