Study on single and double layers micro-perforated panel absorbers and optimal design by genetic algorithm

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Base on Maa's general theory of micro-perforated panel absorber, the acoustic absorption performance of single and double layers MPP absorbers are investigated. The analytical formula for calculating the absorption coefficient of single and double layers micro-perforated panel are derived by the equivalent circuit method. Meanwhile, sound absorption characteristics of MPP absorber is determined by its structure parameters such as orifice diameter, panel thickness, the perforation ratio, and the depth of the backed air cavity. The influence rule of the variation of the structure parameters on the absorption performance has been studied through numerical simulation with Matlab software. Compared with single structure, the double layers MPP absorber improve the absorption frequency bandwidth effectively. Finally, optimize the double layers MPP absorber's structure parameters by genetic algorithm method. The optimization result improved the average absorption coefficient, and broad frequency absorption bandwidth remarkably at the same time.