A validation of some recent BEM and FEM techniques for predicting exterior acoustic transfer functions for a mockup of an engine installed in the engine bay

As legislation for exterior automotive noise has recently become more challenging, the industry is looking into further optimizing engine and engine bay design. Together with the new legal evolutions, also the engine downsizing trend and therewith the increased use of for instance direct injection and air loading systems requires re-evaluation of the current design guidelines and dedicated studies to reach the quietest design. Simulation provides a relatively inexpensive approach to accomplish this: many design alternatives can be tested before any prototype is actually tested. In order for the simulation path to be successful, it is paramount that the approaches are sufficiently fast and accurate. This paper discusses some of the more recent evolutions in Finite and Boundary Element Methods and their solver technologies. The case study concerns prediction of acoustic transfer functions for an engine bay mockup model. Results are overlaid with measurements and the time and memory performance of each method is compared.