A sound field reconstruction method for a surface of revolution based on near-field acoustic holography

Abstract

The invention discloses a method for reconstructing the sound field of a curved surface of revolution based on near-field acoustic holography technology. Using the sound pressure information measured on the cylindrical holographic surface, the statistically optimal cylindrical surface near-field acoustic holography technology is used to reduce the reconstruction distance and improve the reconstruction. Accuracy, the application of spherical wave superimposed near-field acoustic holography technology overcomes the limitation that the statistical optimal method can only reconstruct the regular cylindrical sound field, and realizes the reconstruction of the radiation sound field of the shell structure based on the cylindrical measurement surface of any rotary surface shape, placing multiple spherical surfaces The wave source replaces a single spherical wave source, which overcomes the limitation of the method on the shape of the sound field, and effectively suppresses the negative impact of errors in high-order spherical waves on the reconstruction accuracy and stability. Numerical simulations fully demonstrate the effectiveness of the method, which can Reconstruct and visualize the radiation sound field at any point in the three-dimensional space of the surface-of-revolution shell structure, so as to intuitively obtain the sound radiation characteristics of different regions of the external sound field of the structure and the location of the bright spots of the sound field.

Description

technical field [0001] The invention belongs to the field of acoustic radiation signal processing of mechanical structures, in particular to a method for reconstructing a sound field of a curved surface of revolution 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 distance of ships, and is conducive to improving the comprehensive combat capabilities of ships. Accurately locating the strong radiation area of ​​mechanical noise on the surface of the hull is the premise and basis for in-depth study of the transfer characteristics of mechanical sound sources and quantitative separation of mechanical noise contributions. [0003] Nearfield Acoustic Holography (Nearfield Acoustic Holography, NAH) collects the sound waves emitted by the sound source through the microphone array, ...

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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