Calculation of the acoustic radiation of a parallelepipedic structure by using acceleration measurements. Part 2: Determination of the acoustic radiation contribution of each vibrating side

In the case of an existing machine, it is important to know the contribution of each part of the machine to the total acoustic radiation. One can thus identify main phenomena and estimate the gain earned by such or such way of noise reduction. A simple calculation software based on the vibrating measurements on the machine body is proposed to reply there. The theory has been presented in the first part of the article. The software has been used in the case of the radiation of a rectangular box, located on a rigid baffle, with two vibrating faces.
The calculated and measured pressure at one point is similar in the [0-3000] Hz frequency range except in some narrow frequency ranges.
The measured and calculated acoustic power does not present such zones, and the contribution of each plates to the total acoustic radiation can be obtained from the calculation of partial and total acoustic powers on the [0-4000] Hz frequency range.
In the chosen experimental case, the calculation of total and partial acoustic powers based on the only vibrating data knowledge, can be a perform ant tool for vibroacoustic diagnostic.