tube-extended mufflers within specified back pressures using a particle swarm method

Research on new techniques of single-chamber mufflers hybridized with an internal extended tube has been addressed; however, the research work on a space-constrained multi-chamber muffler hybridized with multiple internal extended tubes which may increase the acoustical performance within a specified back pressure has been ignored. Therefore, the analysis of a sound transmission loss (STL) for a tube-extended muffler equipped with 1~3 chambers within a limited space and a specified pressure drop is essential. In this paper, the four-pole system matrix for evaluating acoustic performance ― sound transmission loss (STL) ― is derived. Moreover, a particle swarm optimization (PSO) has been used during the optimization process. Before dealing with a broadband noise, for a reliability check on the PSO method, the STL’s maximization at a pure tone is introduced. In addition, an accuracy check of the mathematical model is also performed. To understand the acoustical ability of the internal extended tubes and chambers inside a muffler, three kinds of multi-chamber mufflers hybridized with extended tubes (one-chamber, two-chamber, and three-chamber mufflers) have been assessed and compared. Correspondence/Reprint request: Dr. Min-Chie Chiu, Department of Mechanical and Automation Engineering, Chung Chou University of Science and Technology, Taiwan 104, R.O.C.. E-mail: [email protected]