Shape optimization of reactive-dissipative mufflers.

Abstract

The optimization problems based on genetic algorithms and the use of finite element method to represent physical models have been used as a design tool in different areas of acoustics. This study utilizes the interaction of these methods to build a software that allows adjusting the user requirements by optimizing the acoustic performance of a muffler under space constraints and also considering a backpressure to be inserted into the exhaust system of an internal combustion engine. The research focuses on developing a programming code and user interface, taking into account that the user of the software has relevant knowledge on the subject. Theoretical results are presented for three types of silencers: simple, double, and triple expansion chambers, incorporating sound absorbing material in the different chambers. At the end of the investigation, results of the measurements made to a few mufflers are presented and compared with the theoretical results.