Exhaust volume i.e. exhaust silencer, for reducing acoustic emissions from exhaust line of internal combustion engine of motor vehicle, has wall with porous material whose air passage resistance has specific Newton-second per cubic meter

摘要

The volume (2) has a body (4) including a separation wall (14) arranged inside a metal tubular envelope (10) for defining inner exhaust gas releasing chambers. The wall comprises flexible porous material (30) whose air passage resistance obtained by Darcy's law ranges from 500 to 2000 Newton-second per cubic meter. The Darcy's law is defined by a relationship comprising parameters such as static pressure difference and macroscopic velocity module of fluid inside pores. A maintaining unit i.e. lattice (32), maintains the porous material. The porous material is chosen from woven or interlaced metallic yarn or structured mineral material such as glass fiber based textile material or metallic foam based textile material.