Apparatus for damping resonance in a conduit
AssigneeVolvo Lastvagnar AB
InventorsGert-Ove WAHLSTROM, Bjorn HENRIKSSON
Life of this patent
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Abstract
Method and apparatus for damping resonance in a conduit (10) utilized for transporting exhaust gases from an internal combustion engine. The resonance is damped by virtue of the conduit (10) being provided with at least one perforation (14) located at a distance from the outlet end (11) of the conduit.
Claims11
An apparatus for damping resonance in a conduit (10) for transporting exhaust gases from an internal combustion engine, which conduit (10) is provided with at least one perforation (14) located at a distance from the outlet end (11) of the conduit and at a point in the conduit (10) with a comparatively lower static pressure than downstream therefrom, the perforation (14) forming an acoustic connection between the interior of the conduit (10) and the surrounding atmosphere.
A method for affecting acoustic attenuation of resonant exhaust noise produced by a combustion engine, said method comprising:
- providing a combustion engine with an exhaust conduit having a length that causes a high magnitude resonant acoustic sound to be experienced in the exhaust conduit as the combustion engine passes through an exhaust resonance producing speed range;
- and
- attenuating the magnitude of the high magnitude resonant acoustic sound at an outlet of the exhaust conduit by causing at least a portion of the high magnitude resonant acoustic sound to diffuse outside the exhaust conduit upstream of the outlet.
Dependencies are inferred from the claim text.