In this paper, accurate measurements of micro-perforated panels were used to verify existing theories. With the continuing development of standing wave tube procedures, the latest four microphone measurements can provide more accurate results than before. A non-switching microphone procedure was used in the experiments to minimize measurement errors. The precise experiments showed that the current Maa theory underestimates the real part of the perforate impedance, which is associated with the resistive end correction. Thus an improved Maa model was proposed that also accounts for the holes’ interactions. A new finite element model of micro-perforated panels was also validated in this work, and the results indicate that it can give an acceptable match with measurements.
Microperforated panels, End corrections, Transfer impedance, Maa model, Four-microphone standing wave tube
Acoustics and Noise Control
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