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A new metal foam material for diesel particulate filtration, trademarked as INCOFOAM® HighTemp, was recently presented. Extensive tests showed the potential of achieving filtration efficiencies of the order of 85% or more at low pressure drop using a radial flow design concept with graded foam porosity. By applying a catalytic washcoat, the foam exhibits enhanced gas mixing and thus higher conversion efficiencies at high space velocities. In addition, due to an excellent soot-catalyst contact, the washcoated foam exhibited high catalytic regeneration rates. The present paper focuses on a novel “cross-flow” design concept for a better filtration/pressure drop trade-off as well as application of the foam as an oxidation catalyst substrate. The experimental testing starts from small-scale reactors and proceeds to real exhaust testing on the engine bench as well as vehicle tests on the chassis dynamometer and on-road testing.

An alternative metal foam substrate for exhaust aftertreatment applications has been recently presented and characterized. The present paper focuses on the potential of the metal foam technology as an efficient DOC and CDPF substrates on real-world conditions. The target platform is a mid-size passenger car and the methodology includes both modeling and experiments. The experimental testing starts from small-scale reactor characterization of the basic heat/mass transfer properties and chemical kinetics. The results show that the foam structure exhibits excellent mass-transport properties offering possibilities for precious metal and catalyst volume savings for oxidation catalyst applications. These results are also used to calibrate an advanced 2-dimensional model which is able to predict the transient filtration and reaction phenomena in axial and radial flow systems.

The pressure for compact and efficient deNO systems has led to increased interest of incorporating SCR coatings in the DPF walls. This technology could be very attractive especially if high amounts of washcoat loadings could be impregnated in the DPF porous walls, which is only possible with high porosity filters. To counterbalance the filtration and backpressure drawbacks from such high porosity applications, the layered wall technology has already been proposed towards minimizing soot penetration in the wall and maximizing filtration efficiency. In order to deal with the understanding of the complex interactions in such advanced systems and assist their design optimization, this paper presents an advanced modeling framework and selected results from simulation studies trying to illustrate the governing phenomena affecting deNO performance and passive DPF regeneration in the above combined systems.

The transient heat transfer behavior of an automotive catalytic converter has been simulated with OpenFOAM in 1D. The model takes into consideration the gas-solid convective heat transfer, axial wall conduction and heat capacity effects in the solid phase, but also the chemical reactions of CO oxidation, based on simplified Arrhenius and Langmuir-Hinshelwood approaches. The associated parameters are the results of data in literature tuned by experiments. Simplified cases of constant flow rates and gas temperatures in the catalyst inflow have been chosen for a comprehensive analysis of the heat and mass transfer phenomena. The impact of inlet flow temperatures and inlet flow rates on the heat up characteristics as well as in the CO emissions have been quantified. A dimensional analysis is proposed and dimensionless temperature difference and space-time coordinates are introduced.