An Improved Method Combining Beamforming and Acoustical Holography for the Reconstruction of the Sound Pressure on Structure Surface

作者：Fu, Qiang; Li, Min^*; Wei, Long; Yang, Debin

来源：Acta Acustica United with Acustica, 2014, 100(1): 166-183.

DOI：10.3813/AAA.918696

With the increasing velocity of the aerospace vehicle, researchers are increasingly concerned with the study on thermal-acoustic fatigue of the vehicle structure. The distribution and absolute values of the sound loads on the structure surface are essential to build the mechanism model of and the fatigue for the safety evaluation of structural failure. The thermal acoustic fatigue experiments are, however, conducted in high temperature environment, where the microphone array cannot be placed to acquire the near-field data and the array configuration is limited. On the other hand, by using the measurement in the far-field, only the distribution of the sound loads on the structure surface can be examined. In this paper, an improved method combining beamforming and the acoustical holography to reconstruct the sound pressure value in the sound field is studied. With the proposed method, traditional beamforming is firstly replaced by the Distance-Weighted beamforming to achieve the sound field reconstruction from the far-field to the near-field. The output data from the Distance-Weighted beamforming serves as the data of the virtual hologram surface, which are then used to achieve the reconstruction from the near field to the surface of the sound source by acoustical holography. The method can be used to reconstruct the sound field in the high temperature environment by using the distribution and the value of the acoustic loads on the surface. Extensive sound field reconstruction experiments in free field and common indoor space have been conducted in different sound source conditions, such as different sound pressure amplitude, frequency and frequency band width. The feasibility of this method is verified. The method proposed has advantages in practical application such as feasibility in severe environment, low numbers of microphones, practical measurement in the far field surface, accurate reconstruction of the sound pressure distribution and the amplitude on the surface of sound source.

• 出版日期2014-2
• 单位北京科技大学