Visualization of Rotating Machinery Noise Basedon Near Field Acoustic Holography
In order to study the problem of rotating mechanical noise source identification, a time-space complex envelope model of monopole sound source is proposed, and the modulation method of complex envelope is given. According to the characteristics of the acoustic field radiation of the rotating mechanical noise source, different measurement distances, reconstruction distances and measurement points are selected to reconstruct the sound field. The simulation analysis results show that the near-field acoustic holography technology still obtains high acoustic field reconstruction accuracy under the condition of large reconstruction distance and requires few sampling points. Even with less measurement points, this method can obtain a better accuracy of acoustic field reconstruction. Using the envelope modulation technique to extract the envelope information and reconstruct the acoustic field can accurately identify the number of sound sources and geometric position distribution, speed up the data processing speed and ensure the reconstruction accuracy of the acoustic field.