This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Optimization of the Flow in Catalytic Converters of Internal Combustion Engines by Means of Screens
Technical Paper
2004-01-3230
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
This work analysis the causes and presents solutions for the non-uniform distribution of the flow in an automotive catalytic. The catalytic converters are usually installed in the exhaust pipe of the vehicle, with a diffuser connect ivy housing of the monolithic ceramic. The diffusers currently used do not provide a good performance, because of their high area ratio (A > 3) and large divergence angle (2θ > 10°). Due to boundary layer separation on the walls of the diffuser, the flow occurs in the form of a “jet”, with high speeds at the center. The non-uniform distribution of the flow causes an irregular use of the catalytic area. The results are an increase in the production costs, in the pressure drop and in the time to “light-off”. In this work, the non-uniformity of the flow was measured with a Pitot tube, in an experimental rig specially designed for this purpose. The insertion of screens in the diffuser perpendicular to the flow can reduce the adverse gradient of pressure, avoiding the separation of the boundary layer. The screens were tested to find the correct mesh and the ideal position in the diffuser. One or more screens can be used, depending on the level of uniformity required. The experiments showed that this method of flow control is capable of producing a uniform velocity profile. If was also found that the method does not significantly affect the total head loss in the catalytic converter.
Recommended Content
Citation
Arantes, E. and de Medeiros, M., "Optimization of the Flow in Catalytic Converters of Internal Combustion Engines by Means of Screens," SAE Technical Paper 2004-01-3230, 2004, https://doi.org/10.4271/2004-01-3230.Also In
References
- Zhao, F. Q Liu, Y. Chue, T. H. Lai, M. C. “Transient Flow Characteristics Inside the Catalytic Converter of Fire Gasoline Engines” SAE Papers 971014 1997
- Wendland, D. W. Matthes, W. R. “Visualization of Automotive Converter Internal Flows” SAE Papers 861554 1986
- Mehta, R. D. “The Aerodynamic Design of Blower Tunnels With Wide Angle Diffusers” Prog. Aerospace Science 18 59 120 1977
- Mehta, R. D. “The Design of Wide Angle Diffusers” Imperial College of Science and Technology I.C. Aero Report 76-03 June 1976
- Angele, B. Kirchner, K. “The Poisoning of Noble Metal Catalysts by phosporus Compounds - III: The Depositetion of Catalyst Poisons in Honeycomb Catalysts” Chemical Engineering Science 35 2101 2105 1980
- Owen, P. R. “Pneumatic Transport” Journal of Fluid Mechanic 20 225 242 1969
- Usui, K. Aoki, S. Inoue, A. “-Shaped Bend in Vertical Plane” J. of Nuclear Science and Technology 17 675 887 1980
- Jobson, E. Hogberg, E. Weber, K. H. Smedler, G. Lundgren, S. Romare, A. Wirmark, G. “Spatially Resolved Effects of Deactivation On Field-Aged Automotive Catalysts” SAE Paper 910173 1991
- Bressler, H. Rammoser, D. Neumaier, H. Terres, F. “Experimental and Predictive Investigation of a Close Coupled Catalytic Converter With Pulsating Flow” SAE Paper 960564 1996
- Mehta, R. D. Bradshaw, P. 1979 “Design Rules for Small Low Speed Wind Tunnels” Aeronautical Journal November 1979 443 449
- Day, J. Paul Socha Jr Louis S. “The Design of Automotive Catalyst Supports for Improved Pressure Drop and Conversion Efficiency” SAE Paper 910371 1991
- Leveroni, E Carpegna, G Vafidis, C. “Analisi Sperimentale Della Maldistribuzione Del Flusso In Convertitori Catalitici” Italia
- Arantes, E. M. R. “Otimização do escoamento em Um Catalisador Automotivo Pelo Uso de Telas” Pontifícia Universidade Católica de Minas Gerais dezembro 2001
- Arantes, E. M. R Medeiros, M. A. F. “Investigação Experimental do Escoamento em Um Catalisador Automotivo” SAE Paper 000216 2001
- Cockrell, D.J. Markland, E. “Diffuser Behavior” A Review of Past Experimental Work - Relevant Today Aircraft Engineering 46 16 35 286 1974
- Schubauer, G.B. Spangenberg, W.G. “Effects of Screens in Wide Angle Diffusers” NACA TN-1610 1948
- Wieghardt, K. E. G “On the Resistance of Screens” Aero Quarterly 4 186 1953