Impact of Manifold Design on Flow Distribution of a Close-Coupled Catalytic Converter

Salasc, S.; Barrieu, Edouard; Leroy, Vincent

doi:10.4271/2005-01-1626

Cited by 20 publications

(4 citation statements)

References 8 publications

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“…This issue becomes even more significant if the catalytic convertors are mounted close to the engine (i.e., to minimize cold-start emissions). In these compact packaged convertors, the monolith close to the engine due to the installation limit can lead to widely non-uniform flow behaviour [27,28], as shown in Figure 1, the compact design will potentially affect the performance due to this non-uniformity.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the Flow Field from Connection Cones to Monolith Reactors

Sjöblom

Ström

et al. 2019

Energies

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The connection cones between an exhaust pipe and an exhaust after-treatment system (EATS) will affect the flow into the first monolith. In this study, a new streamlined connection cone using non-uniform rational B-splines (NURBS) is applied to optimize the flow uniformity inside two different monoliths (a gasoline particulate filter and an un-coated monolith). NURBS and conventional cones were created using 3D printing with two different cone angles. The velocities after the monolith were collected to present the uniformity of the flows under different cones and different velocities. The test results indicate that NURBS cones exhibit better performance. Furthermore, all of the pressure drops of the bench test were measured and compared with those of the conventional cones, demonstrating that the NURBS cones can reduce the pressure drop by up to 12%. The computer fluid dynamics simulations depict detailed changes in the flow before and after entering the monolith. The results show that the NURBS cone avoids the generation of a recirculating zone associated with conventional cones and creates a more uniform flow, which causes a lower pressure drop. Meanwhile, the package structure of the NURBS cone can reduce the space requirements. Finally, the implications of the flow distributions are discussed.

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Section: Introductionmentioning

confidence: 99%

Analysis of the Flow Field from Connection Cones to Monolith Reactors

Sjöblom

Ström

et al. 2019

Energies

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“…However, such a difference is sufficient to impact significantly the flow distribution. It should be pointed out that there have been several efforts on improving the flow distribution inside a catalytic converter by adding diffuser elements, changing the inlet cone, and similar solutions [15,[43][44][45], but using an optimized combination of cell densities, washcoat loading, and so on, has not been explored extensively yet.…”

Section: Evenly Distributed Dual Cell Densitymentioning

confidence: 99%

On the Use of Dual Cell Density Monoliths

2021

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Monolith-type substrates are extensively used in automotive catalytic converters and have gained popularity in several other industrial processes. Despite their advantages over traditional unstructured catalysts, such as large surface area and low pressure drop, novel monolith configurations have not been investigated in depth. In this paper, we use a detailed computational model at the reactor scale, which considers entrance length, turbulence dissipation and internal diffusion limitations, to investigate the impact of using a dual cell substrate on conversion efficiency, pressure drop, and flow distribution. The substrate is divided into two concentric regions, one at its core and one at its periphery, and a different cell density is given to each part. According to the results, a difference of 40% in apparent permeability is sufficient to lead to a large flow maldistribution, which impacts conversion efficiency and pressure drop. The two mentioned variables show a positive or negative correlation depending on what part of the substrate—core or ring—has the highest permeability. This and other results contribute relevant evidence for further monolith optimization.

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“…Reducing the cone expansion angle represents another method of improving the flow distribution [34]. Moreover, the monolith has an installation limit, and if it is close to the engine, it can lead to highly nonuniform flow behavior [35,36], which will affect the monolith performance.…”

Section: Connection Cone Optimizationmentioning

confidence: 99%

Experimental Study on the Flow Field of Particles Deposited on a Gasoline Particulate Filter

Sjöblom

Sharma

et al. 2019

Energies

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The abatement of particulate matter in gasoline vehicle exhaust has prompted the development of gasoline particulate filters (GPFs). The spatial distribution of the deposited particles inside a GPF has profound implications for its regeneration behavior, ash-induced aging, and multiscale modeling efforts. The connection cones will affect the flow into the monolith and the package structure needed to meet the system space requirements. In this paper, nonuniform rational B-splines (NURBSs) were applied to the cone design to optimize the flow uniformity and particle distribution inside a gasoline particulate filter. NURBS and conventional cones were manufactured using 3D printing, and the velocity profiles and pressure drops were measured under the loading of synthetic particles. The results shows that the cone shape will influence the pressure drop and the velocity profile, which is evaluated as the uniformity index. The test results indicate that better performance is achieved when using the NURBS cone, especially at low particle loads. The results also show that the cone shape (which determines the velocity profile) influences the particle deposition distribution, although the apparent pressure drops are similar. These results are important for exhaust aftertreatment system (EATS) design and optimization, where the NURBS cone can improve flow uniformity, which causes better particle deposition distribution and lower pressure drop.

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Impact of Manifold Design on Flow Distribution of a Close-Coupled Catalytic Converter

Cited by 20 publications

References 8 publications

Analysis of the Flow Field from Connection Cones to Monolith Reactors

Analysis of the Flow Field from Connection Cones to Monolith Reactors

On the Use of Dual Cell Density Monoliths

Experimental Study on the Flow Field of Particles Deposited on a Gasoline Particulate Filter

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