Micro-perforated panels (MPP) have a good acoustic damping performance and a potential to be used in mufflers. This project aims to investigate the acoustic performance of a parallel baffles muffler, which consists of MPP baffles. The work is both experimental and numerical, i.e., a model is developed for a MPP baffles muffler with local reaction. The prototype MPP mufflers tested in the thesis were alal produced by the Swedish company Sontech.
First, the experiments were based on the procedure for experimental characterization of heat exchangers described in Ref. . The transmission loss and flow generated sound are tested at four flow speeds for seven kinds of parallel baffles. Second, the mathematical modeling is built on the basis of the standard models of a locally reacting liner muffler . The impedance for the Micro-perforated panels is computed using the models described by Maa and Guo.
Author: Xiaowan, Su