Acoustical Holography Technology for Surface Noise Sources Location on Underwater Cylindrical Shell Structure

Abstract

Cylindrical Multi-reference Statistically Optimized Near-field Acoustical Holography technology is proposed to apply to surface noise sources locating on underwater cylindrical shell structure. Implementing process of the proposed noise sources locating technology, is compose of arranging reference points for the aimed system, carrying out partial sound field decomposition, reconstructing partial sound field on reconstruction surface and assembling composite vector of sound field on reconstruction surface with partial sound field in theory, and also composed of discrete sampling of continuous measure signals, eliminating measure noise, filtering for discrete signals and spanning virtual reference subspace with principal components extracted by coherence noise source in algorithm. The proposed noise sources locating technology is employed to realize visually location of surface noise sources on underwater cylindrical shell structure, and its numerical simulation is carried out. Results of numerical simulation show that: high resolution is obtained in vicinity of noise source, complex acoustic pressure spectrum is focused on the center of noise source on reconstruction surface, accurately location of noise source is realized, locating results of noise source are influenced by some factors, e.g. finite measurement aperture, filters' parameters in wave number-domain and parameters of sound projection algorithm, and the optimized location of noise source is obtained when properly considering the factors.