Numerical optimization for acoustic performance of the micro-perforated plate and its application in high-speed trains

Currently, researches on the acoustic radiation efficiency and sound insulation performance of the micro-perforated plate mainly focused on the experimental test, and the numerical simulation is rarely reported. In this paper, firstly, the discrete element method was applied to test the acoustic radiation efficiency of the micro-perforated plate. It was shown that the experimental result was reliable, which made up for the deficiency of the traditional vibro-acoustic test method. Secondly, the pulse decay method was used to test the damping loss factor of the perforated plate. Then, the transfer admittance on both sides of the micro-perforated plate was computed to simulate the properties of the hole. Finally, the damping loss factor and admittance were imported into the boundary element model (BEM) of the micro-perforated plate, in order to compute the transmission loss, and it was compared with that of the experimental test. As shown from the compared result, the sound insulation performance of the micro-perforated plate can be predicted effectively using this method. Based on the verified simulation model, the impact of the hole diameter, plate thickness and perforation rate on sound insulation performance of the perforated plate was studied. However, each structural parameter of the perforated plate can't be optimal through the above analysis. As a result, an optimization design was conducted on it based on the improved genetic algorithm. Finally, the perforated plate which had the optimal structural parameter and performance was obtained. Finally, the optimized perforated plate was applied on the high-speed train, and the experimental results showed that the interior noise in the high-speed train was reduced obviously.