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Effect of Catalyst Inlet Cone Flow Mal-Distribution on Emissions Performance of a Close-Coupled Catalytic Converter
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 08, 2004 by SAE International in United States
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The emissions performance of a prototype close-coupled catalyst system has been analysed and compared with semi-close-coupled and underfloor systems.
Under certain engine conditions during the stabilized region of the ECE Stage 3 drive-cycle, the close-coupled system has showed higher emissions than the semi-close-coupled or underfloor configurations. Using fast response emissions analysers and catalyst warm-up characteristics in conjunction with Computational Fluid Dynamics (CFD), the reasons for this emissions performance deficit has been attributed to flow maldistribution across the front face of the catalyst.
Two flow distribution-related mechanisms for emissions breakthrough have been isolated: radial variations in mean AFR (Air-Fuel Ratio) across the catalyst can cause localized emissions breakthrough due to cylinder-to-cylinder AFR variations; and under high space velocity conditions, localized breakthrough can occur due to radial variations in gas velocity through the catalyst.
- Bruce Campbell - Cambustion Ltd.
- Alex Finch - Cambustion Ltd.
- Paul Tancell - Dunton Technical Centre, Ford Motor Company Ltd.
- Andrew Hitchings - Dunton Technical Centre, Ford Motor Company Ltd.
- Mark Marsh - Dunton Technical Centre, Ford Motor Company Ltd.
- David Lloyd-Thomas - Dunton Technical Centre, Ford Motor Company Ltd.
- David Gregory - Dunton Technical Centre, Ford Motor Company Ltd.
CitationCampbell, B., Finch, A., Tancell, P., Hitchings, A. et al., "Effect of Catalyst Inlet Cone Flow Mal-Distribution on Emissions Performance of a Close-Coupled Catalytic Converter," SAE Technical Paper 2004-01-1489, 2004, https://doi.org/10.4271/2004-01-1489.
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