Transmission loss assessment and optimization of an intake system for automotive application

The acoustic project of internal combustion engine's intake systems is a very important task aimed to ensure that a tradeoff between noise emissions and perceived sound quality is achieved. In general, the most used parameter for characterizing the performance of an acoustic filter is represented by the so called Transmission Loss which may be numerically evaluated thanks to a three-dimensional FEM code. In this paper, a FEM model of an intake system for a commercial spark ignition engine has been realized in order to simulate its acoustic performance in terms of Transmission Loss, without considering structural participation as well as the presence of mean flow inside the system. After a model validation, thanks to previous experimental analysis, an acoustic optimization procedure of the studied system has been carried out by means of geometry modifications.