Optimization of multi-size micro-perforated panel absorbers using multi-population genetic algorithm

Micro-perforated panel (MPP) absorber with multi-size holes is a new type of broad band sound absorber which is thin, durable, clean and environmentally friendly. These advantages make it especially suitable for applications in the narrow space. However, so far it has not been widely used partially because of its design complexity. The absorption performance of a single MPP absorber with uniform-size perforations depends on four structure parameters: the hole diameter, the perforation ratio, the panel thickness and the cavity depth. It is possible to find an appropriate combination of these parameters that provides sound absorption in one or two octave bands within the frequency range of interest for noise control applications. However, the design of an N-size MPP absorber depends on 2 + 2N parameters which greatly increases design complexity. To overcome this problem, multi-population genetic algorithm (MPGA) is proposed in this study for the optimization design of a multi-size MPP absorber. A theoretical model of multi-size MPP absorbers is developed firstly and then its validity is verified by experimental data. Thereafter, a program for optimizing for wide band noise over a specified frequency range has been created and run. Results indicate that MPGA provides a fast and efficient approach for designing multisize MPP absorbers.