In recent years, low and mid frequency analysis of engine has shown that many design decisions influenced negatively the acoustic performance of engines. To counteract this problem, design engineers have started to design engine covers that actually reduce the noise radiated before it gets
too far from the engine. These methods basically modify the path the noise would take to get to a vehicle occupant’s ear. Another approach is to modify the design of the engine construction itself in order to reduce the noise generated at the source. This paper presents a method to predict radiated
noise from an engine for the full frequency domain of analysis (0-10000 Hz). This approach combines the Finite Element Method (FEM) to represent the structure and its load cases and the new Fast Multipole Boundary Element Methods (FMM-BEM) to represent the fluid surrounding the engine. This approach allows engineers to add acoustics to their existing structural predictions and investigate the effect on radiated sound power of modifying the structure, adding beads, adding damping treatment or acoustic covers in the vicinity of an engine. Typical engine noise radiation results with these changes along with cases with and without acoustic covers are presented and discussed.
2011 – DAGA, Düsseldorf, Germany
Denis Blanchet (ESI Group, Germany)
Arnaud Caillet (ESI Group, Germany)