DISTANCE-WEIGHTED BEAMFORMING FOR THE RE- CONSTRUCTION OF THE SOUND PRESSURE ON STRUCTURE SURFACE

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, the DistanceWeighted Beamforming is studied for reconstructed sound field pressure, which weights the array signals of traditional Beamforming by a distance parameter based on the theory of the acoustic attenuation. Extensive sound field reconstruction experiments in free field and common indoor space have been conducted in different sound pressure amplitude, frequency and frequency band width. The effectiveness of this method is verified. The method proposed has advantages in practical application of the accurate reconstruction of the sound pressure distribution and amplitude on the near-field surface of the sound source in severe environment by measurement in the far field surface.