Effect of Catalyst Inlet Cone Flow Mal-Distribution on Emissions Performance of a Close-Coupled Catalytic Converter

2004-01-1489

03/08/2004

Event
SAE 2004 World Congress & Exhibition
Authors Abstract
Content
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.
Meta TagsDetails
DOI
https://doi.org/10.4271/2004-01-1489
Pages
13
Citation
Campbell, 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.
Additional Details
Publisher
Published
Mar 8, 2004
Product Code
2004-01-1489
Content Type
Technical Paper
Language
English