Multi-chambered sound attenuation with resonant frequency targeting

An apparatus for engine exhaust sound attenuation comprising:

• a housing having an interior and an exterior;
• a plurality of baffle plates arranged within the housing, the plurality of baffle plates including at least a first set of matching baffle plates and a second set of matching baffle plates, different from the first set, the plurality of baffle plates being disposed apart from each other to define an inlet chamber at a proximal end of the housing, an outlet chamber at a distal end of the housing, and a plurality of intermediate chambers disposed between the inlet chamber and the outlet chamber, the plurality of intermediate chambers comprising:
• a first resonant chamber proximate to the outlet chamber;
• a second resonant chamber proximate to the inlet chamber;
• a first intermediate chamber proximate to the second resonant chamber;
• and
• a second intermediate chamber proximate to the first intermediate chamber and the first resonant chamber;
• an inlet tube disposed fluidly connected to the housing and configured to direct a flow of exhaust from the exterior of the housing to the inlet chamber;
• an outlet tube disposed fluidly connected to the housing and configured to direct the flow of exhaust from the outlet chamber to the exterior of the housing;
• a first tube configured to direct the flow of exhaust from the inlet chamber to one of the plurality of intermediate chambers via an interior of the first tube;
• and
• a second tube configured to direct the flow of exhaust from a second one of the plurality of intermediate chambers to the outlet chamber via an interior of the second tube.

An engine exhaust system comprising:

• an engine, and a sound attenuation apparatus connected to an exhaust port of the engine, the sound attenuation apparatus comprising:
• a housing having an interior and an exterior;
• a plurality of baffle plates arranged within the housing, the plurality of baffle plates including at least a first set of matching baffle plates and a second set of matching baffle plates, different from the first set, the plurality of baffle plates being disposed apart from each other to define an inlet chamber at a proximal end;
• an outlet chamber at a distal end of the housing;
• and
• a plurality of intermediate chambers disposed between the inlet chamber and the outlet chamber, the plurality of intermediate chambers comprising:
• a first resonant chamber proximate to the outlet chamber;
• a second resonant chamber proximate to the inlet chamber;
• a first intermediate chamber proximate to the second resonant chamber;
• and
• a second intermediate chamber proximate to the first intermediate chamber and the first resonant chamber;
• an inlet tube disposed fluidly connected to the housing and configured to direct a flow of exhaust from the exterior of the housing to the inlet chamber;
• an outlet tube disposed fluidly connected to the housing and configured to direct the flow of exhaust from the outlet chamber to the exterior of the housing;
• a first tube configured to direct the flow of exhaust from the inlet chamber to one of the plurality of intermediate chambers via an interior of the first tube;
• and
• a second tube configured to direct the flow of exhaust from a second one of the plurality of intermediate chambers to the outlet chamber via an interior of the second tube.