Air intake system design: Vibro-acoustic modelling and prediction for commercial vehicles

Vibro-acoustic numerical modelling is used to evaluate the acoustic behaviour of virtual prototypes during the development process of new air intake systems for commercial vehicles. In order to describe this behaviour, the following analyses have been performed: acoustical and structural normal modes using traditional FEM methodology, transfer function with and without fluid structure interaction effects and radiation acoustics analysis using BEM direct approach. To validate the numerical model, NVH engineer teams build physical prototypes for comparison to numerical data. Basically, the NVH teams are responsible for checking the main acoustic influences of the air intake system on pass-by-noise and internal noise tests. The aim of this paper is to describe the vibro-acoustic methodology used, and its relation with engineering teams experimental work. Therefore, experimental tests and virtual acoustics prototypes are compared and. a correlation with the air intake systems acoustic problems are verified to improve the quality of the new air intake system design.