Vibro-Acoustic Modeling and Validation of Fuel Rails for GDI Wet Systems

NVH simulations for an automotive component industry represent a convenient mean to compare different solutions and make decisions on design choices based on the predictions of the component vibro-acoustic behavior. This paper presents the vibro-acoustic characterization and comparison of two fuel rail assemblies (FRAs) by mean of simulations in Ansys Workbench & LMS Virtual.Lab. These simulations required a preliminary finite element (FE) modal analysis on the FRAs. To verify the reliability of the FE models, an experimental modal analysis was performed on one of the two fuel rails in free-free condition. The correlation between FE and test models highlighted some differences: a sensitivity study proved that the differences depend on the modeling of some brazed joints. The results of the following NVH simulations were checked by performing an acoustic impact test on the two FRAs in free-free condition inside an anechoic chamber. The comparison between the test and FE results proved that only a tuned FE model provides reliable results.