Visualization of Rotating Machinery Noise Based on Near Field Acoustic Holography

Abstract

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.