Application of a Virtual Rotating Array for Near-field Localization of Rotating Sound Sources

In recent years, the virtual rotating array method has been developed and applied to beamforming for localizing the sound sources due to rotating objects, such as axial fan, rotating wind turbine blades etc.. However, there are still very few studies dealing with the near-field rotating sound source visualization. In the current study, the virtual rotating array method is proposed to work with near-field holography for localization and visualization of near-field rotating sound source. Firstly, the virtual rotating array signals are synthesized by interpolating the near-field static array measurement. Different interpolation strategies are utilized, and their errors are quantified. Then, the virtual rotating array signals are processed using different holography methods, to reconstruct the near-field sound pressure due to rotating sources. Numerical validations have been performed using the simulated sound signals. The simulation results have demonstrated that the near-field sound sources can be reconstructed successfully with high accuracy using the proposed approach.