A SILENCER AND A METHOD OF OPERATING A VEHICLE

摘要

A device (a silencer) for silencing a flow, comprises at least one acoustic chamber through-flowed by gas, e.g., exhaust gas, at least one inlet pipe an d at least one pipe or passage interconnecting two chambers or a chamber and a n exterior environment or chamber and is designed with such cross-sectional ar ea transitions between passages and the chambers that the sound attenuation achieved by the device is high while the pressure drop across the silencer i s low and that high attenuation at low characteristic frequencies of flow systems comprising the device are obtained. One or more diffusers and/or monolithic bodies or catalysts may be comprised in the device. The passages may be curved or helical so as to allow for a low natural frequency. Embodiments with resonance chambers attenuating at selected frequencies are disclosed. A method for operating a vehicle comprising a combustion engine a nd a silencing system is disclosed.