Acoustic particle velocity measurement by ultra-light membrane and its applications in acoustic holography

Abstract

Acoustic holography is a non-destructive method used to determine the spatial propagation of acoustical waves. Conventionally, the acoustic holography measures the acoustic pressure. Until recently, a very limited number of techniques to measure the acoustic particle velocity have been introduced. The Laboratory of Vibration and Acoustics of INSA de Lyon, France has recently developed a novel method to directly measure the acoustic velocity field by a light membrane, with the assistance of a laser vibrometer. Theories allowing getting acoustic pressure and acoustic power from particle velocity have also been developed. The primary goal of this project is to apply the recently developed theories to a series of acoustic measurements. The objectives consist of the validation of the method and the evaluation of its performances under various circumstances. In several experiments, results obtained by the approach of membrane?s measurement are compared with results from conventional microphone?s measurement and a relatively new P-U probe measurement.