ENGINE SYSTEM WITH TURBULENCE ASSISTED DAMPING OF LOW FREQUENCY SOUND

摘要

The present disclosure relates to an engine system comprising an ICE; an exhaust system; and an engine control unit for controlling operation of the engine system between at least a first operating state resulting in a first exhaust temperature range, and a second operating state resulting in a second, higher, exhaust temperature range. The exhaust system comprises a low frequency sound attenuation portion including a first tubing section having a first flow area; a second tubing section, having a second flow area smaller than the first flow area; and a third tubing section having a third flow area greater than the second flow area. The low frequency sound attenuation portion is dimensioned to achieve laminar flow through the third tubing section when the engine system is in the first operating state; and turbulent flow through the third tubing section when the engine system is in the second operating state.

主权项

1. An engine system comprising:
an internal combustion engine having at least one combustion chamber and an exhaust manifold for conducting exhaust fumes away from the at least one combustion chamber; an exhaust system forming a flow path between an inlet in fluid flow connection with the exhaust manifold and an outlet; and an engine control unit for controlling operation of the engine system between at least a first operating state resulting in a first exhaust fume temperature range, and a second operating state resulting in a second exhaust fume temperature range substantially higher than the first exhaust fume temperature range; wherein the flow path of the exhaust system comprises a low frequency sound attenuation portion including: a first tubing section having a first flow area; a second tubing section, directly downstream of the first tubing section, having a second flow area smaller than the first flow area; and a third tubing section, directly downstream of the second tubing section, having a third flow area greater than the second flow area; wherein the first, second and third tubing sections are dimensioned in such a way that: a flow of the exhaust fumes through the third tubing section is laminar when the engine system is controlled by the engine control unit to be in the first operating state; and the flow of the exhaust fumes through the third tubing section is turbulent when the engine system is controlled by the engine control unit to be in the second operating state.