Three-Dimensional Acoustic Analysis and Design Optimization of Straight and Reversing Muffler Systems

• Main Authors: Shiuan-En Huang, 黃萱恩
• Other Authors: Ying-Chun Chang
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/58225819458292475217

碩士 === 大同大學 === 機械工程學系(所) === 103 === According to plane wave theory, the sound will propagate in mufflers only in a plane wave type at low frequencies; however, for a high frequency, the higher-order mode effect occurred will result in a difference between the measurement and the theory. Currently, the acoustical analysis of three-dimensional propagating inside a one-chamber muffler has been widely discussed; however, the research work of a multi-chamber hybridized with baffles and reversing muffler is few. Therefore, the acoustical performances of reversing chamber mufflers hybridized with multiple baffles in a three-dimensional acoustic mode will be explored in this paper. In addition, the shape optimization of the space-constrained one-chamber hybridized with various baffles will be fulfilled by adjusting the chamber and inlet/outlet tube size. In this paper, eigen function expansion method will be used to derive the four-port transfer matrix to calculate the acoustic performance of three-dimensional wave propagation in mufflers. Subsequently, analyzing the performance for various mufflers and comparing the theoretical data with the literature yield that the mathematical model of the mufflers is correct. In order to maximize the acoustical performance, the shape optimization of mufflers in conjunction with the genetic algorithm is performed.