Three-way monolithic converter: Simulations versus experiments

Siemund, S.; Leclerc, Jean; Schweich, D.; Prigent, Michel; Castagna, F.

doi:10.1016/0009-2509(96)00018-8

Cited by 96 publications

(57 citation statements)

References 29 publications

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“…A number of mathematical models working in this direction are already presented in the literature and employed in optimization procedures (Oh and Cavendish, 1985;Pattas et al, 1994;Siemund et al, 1996). On the other hand, the research on the e!ect of oscillating A/F has been restricted mainly to experimental testing and empirical explanations of results.…”

Section: Introductionmentioning

confidence: 99%

Modeling dynamic phenomena in 3-way catalytic converters

Koltsakis

Stamatelos

1999

Chemical Engineering Science

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Mathematical modeling of 3-way catalytic converter (3WCC) operation is increasingly employed in automotive catalyst and converter systems optimization. The majority of the models employed in this direction employ a &quasi-steady' approach in the reaction kinetics computations. This approach is useful in predicting real-world performance of the catalyst. However, certain improvements, that are produced by the application of specially tuned redox oscillations, can not be predicted. This paper presents an approach embodying certain types of dynamic phenomena into an existing 3-WCC quasi-steady model. The dynamic model developed according to this approach is validated against literature data and results from experimental investigations. It is con"rmed, that the catalyst behavior under dynamic exhaust composition conditions signi"cantly di!ers from what is predicted under the quasi-steady-state assumption. More speci"cally, oxygen storage and the transient character of water gas shift reaction are shown to a!ect dynamic behavior. The results of this investigation encourage further application of mathematical modeling in areas like lambda control strategy optimization, which lied beyond the scope of traditional 3WCC models.

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Section: Introductionmentioning

confidence: 99%

Modeling dynamic phenomena in 3-way catalytic converters

Koltsakis

Stamatelos

1999

Chemical Engineering Science

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“…Reaction (6), with rate constant k elevated and adjusted is applied to release the stored NO during an appropriate time period. The released NO can then be consumed by the NO/CO reduction reaction, for which kinetics are available in the paper by Siemund et al [14]. The model has the facility that other reaction equations with appropriate kinetics that consume NO x could be alternatively or simultaneously applied, if required.…”

Section: No X Trap Cfd Methodologymentioning

confidence: 99%

Three-dimensional modelling of NOx and particulate traps using CFD: A porous medium approach

Benjamin

Roberts

2007

Applied Mathematical Modelling

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Lean burn after-treatment systems are the current focus for reducing emissions from diesel exhaust. The trend is for commercial CFD packages to use a single channel modelling approach. Due to computational demands, this necessitates specification of representative channels for modelling, implying prior knowledge of the flow field. This paper investigates a methodology for applying the porous medium approach to lean burn after-treatment systems. This approach has proved successful for three-way catalysis modelling and has the advantage that the flow field is predicted. Chemical kinetic rates for NO x trapping and regeneration in the model are based on information available in the open literature. Similarly, filtration information based on mass accumulation and soot combustion kinetics are also readily available. Modification of the source terms in a commercial CFD package enables prediction of trapping and release of NO x . This is an effective way to model a NO x trap after-treatment system and provides simultaneous 3D modelling of the flow field. With diesel, particulate filtration is required. In the case of particulate traps, however, because of channel geometry, some assumptions are necessary for use of the porous medium approach and these are discussed in this paper. Both models produce qualitatively correct output and have parameters that can be tuned to conform to experimental data. Data to validate the NO x trap model is to be measured. The particulate trap model, on the other hand, is a feasibility study for modelling the complete diesel after-treatment system using the porous medium approach.

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“…13 into a nondimensional form by defining the following dimensionless variables (15) where in the interests of isolating the region in the vicinity of the light-off location, it is clear that z 0 5 z lo and Dz ref 5 L, whereas T 0 and DT ref represent as yet undefined reference temperature scaling quantities that will be defined shortly in the analysis that follows. Combining the above scaled variables and the gas phase energy balance in Eq.…”

Section: Spread Of the Light-off Frontmentioning

confidence: 99%

Light‐off location and front diffusion in a catalytic monolith reactor

Ramanathan

Gopinath

2008

AIChE Journal

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in Wiley InterScience (www.interscience.wiley.com).A one-dimensional solid-gas model has been used to study the light-off behavior in a reactor system. Techniques from nonlinear analysis are applied to first arrive at an analytical expression to estimate the light-off location in the reactor. The model is then extended to estimate the thickening of the light-off front in the vicinity of the light-off location due to heat diffusion effects in the solid substrate. Both these results are expressed in terms of all the important operating and design variables of the monolith reactor and also the reaction specific variables such as the kinetic parameters and heats of reaction. A specific case of a three-way catalyst (TWC) is numerically treated in detail to illustrate the application of this work. Finally, we focus on using the insight obtained from this study to suggest design guidelines to optimize the performance of automotive catalytic monolith reactors.

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Three-way monolithic converter: Simulations versus experiments

Cited by 96 publications

References 29 publications

Modeling dynamic phenomena in 3-way catalytic converters

Modeling dynamic phenomena in 3-way catalytic converters

Three-dimensional modelling of NOx and particulate traps using CFD: A porous medium approach

Light‐off location and front diffusion in a catalytic monolith reactor

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