Title: CFD model of multi-converter HC adsorber-TWC system

Authors: Thiyagarajan Paramadayalan; Atul Pant

Addresses: GM Powertrain-India, Engine CAE, GM Tech Center (India), Bangalore 560066, India ' Global General Motors R&D, India Science Lab, GM Tech Center (India), Bangalore 560066, India

Abstract: A novel three dimensional model of in-line hydrocarbon adsorber system (with both adsorber and three-way catalyst) is developed by coupling the computational fluid dynamics (CFD) flow and temperature effects with a 1D chemical kinetics solver. The model has been validated against experimental values obtained from vehicle test over light-off. The overall performance of the multi-converter hydrocarbon adsorber system is compared with a single converter with only three-way catalytic (TWC) monolith. It is observed that thermal mass of the adsorber monolith plays a vital role in determining the performance of total converter system. The impact of diverting exhaust flow away from the hydrocarbon absorber is also established using this model. Results indicate that the cold start hydrocarbon emission is not a monotonous function of the valve opening time. The optimum time for which the adsorber should be exposed to the exhaust depends not only on its adsorption capacity but also on the thermal capacity of adsorber monolith.

Keywords: catalytic converters; hydrocarbon adsorbers; multi-converters; CFD; computational fluid dynamics; mathematical modelling; monolith reactor; chemical kinetics; TWC systems; three-way catalytic systems; 3D modelling; exhaust flow; temperature effects; vehicle emissions; cold start; hydrocarbon emissions; valve opening time; adsorption capacity; thermal capacity.

DOI: 10.1504/IJVD.2016.076739

International Journal of Vehicle Design, 2016 Vol.70 No.4, pp.358 - 376

Accepted: 15 Dec 2015
Published online: 24 May 2016 *

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