Revolution surface sound field reconstruction method based on near-field acoustic holography technology

Abstract

The invention discloses a revolution surface sound field reconstruction method based on a near-field acoustic holography technology. Sound pressure information measured on the cylindrical holographicsurface is utilized; a statistical optimal cylindrical surface near-field acoustic holography technology is applied to reduce the reconstruction distance, so that the reconstruction precision is improved; the limitation that only a regular cylindrical sound field can be reconstructed by adopting a statistical optimal method is overcome by applying a spherical wave superposition near-field acousticholography technology; the reconstruction of the radiation sound field of the shell structure with any revolution surface appearance based on the cylindrical measurement surface is realized; a plurality of spherical wave sources are placed to replace a single spherical wave source, the limitation of the method on the sound field appearance is overcome; negative effects of errors in high-order spherical waves on reconstruction precision and stability are effectively inhibited; the effectiveness of the method is fully displayed through numerical simulation, the radiation sound field of any point of the revolution surface appearance shell structure in the three-dimensional space can be reconstructed, visual display is achieved, and therefore the sound radiation characteristics and the soundfield bright spot positions of different areas of the sound field outside the structure can be visually obtained.

Description

Technical field [0001] The invention belongs to the field of acoustic radiation signal processing of mechanical structures, and particularly relates to a method for reconstructing a rotating surface sound field based on acoustic holography technology. Background technique [0002] Mechanical noise is the main noise source of underwater radiated noise of ships. Controlling mechanical noise is conducive to improving the acoustic stealth performance and detection range of ships, and is conducive to improving the comprehensive combat capabilities of ships. Precisely locating the strong radiation area of ​​mechanical noise on the surface of the hull is the prerequisite and basis for in-depth study of the transmission characteristics of mechanical sound sources and quantitative separation of mechanical noise contributions. [0003] Nearfield Acoustic Holography (NAH) acquires the sound waves emitted by the sound source through a microphone array, and through a sound field transformation ...

AI Technical Summary

Problems solved by technology

However, this method can only reconstruct the radiated sound field of sound sources such as cylinders, spheres, and planes with regular shapes, and the actual sound sources often have irregular shapes and uneven surfaces, so the traditional SONAH method is difficult to apply

The NAH method based on spherical wave superposition is also called Helmholtz Equation Least Squares (HELS). Various irregular-shaped radiation sound fields, but the disadvantage of this method is that it can only reconstruct the spatial sound field with an aspect ratio of approximately 1 due to the influence of the spherical wave radiation characteristics. The reconstruction accuracy of σ decreases rapidly with the increase of the reconstruction distance

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