Transient Simulation of Flow Noise in Exhaust Mufflers
- 51 Downloads
Flow noise is an extremely annoying component of tailpipe noise. It is caused by turbulence and pressure fluctuations, which can be resolved in space and time by transient computational fluid dynamics or Detached Eddy Simulation. This direct simulation of the flow field simultaneously with the noise generation and sound propagation provides the necessary insight and understanding for the optimization of muffler designs, as Faurecia and Siemens demonstrate in the following.
Flow Noise is a Key Challenge
Due to stringent noise emission regulations and increased customer sensitiveness toward disturbing noises, flow noise has to be considered as one of the key issues in the development of exhaust systems. Generated especially at high mass flow rates, flow noise is caused by local production of turbulence and pressure fluctuations in areas with perforated walls or areas with flow separation, flow impingement or free stream jets with strong shear forces. The flow noise can further intensify...