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In order to meet the increasingly stringent emissions standard it is imperative that a two pronged approach is pursued for reduction of tailpipe emissions. In this regard emissions, and often the exhaust compositions, are needed to be controlled both at its source and then subsequently cleaned up at the exhaust system. In addition, an aftertreatment system often consists of an array of catalysts and its performance depends on the transient characteristics of the exhaust gas composition. To complicate the matter furthermore, relevant technologies are still evolving at a rapid pace. Consequently, an aftertreatment modeling approach should not only be system based but also offer a high level of configurability. Thus a system level approach that includes a model of an engine and vehicle may provide an efficient means to analyze system performance and examine relative effects of competing phenomena and technologies.

In order to reduce the cost of exhaust aftertreatment development, OEMs are increasingly relying on simulation of catalysts, traps and associated control systems. In this regards, for example, considerable progresses have been made on modeling diesel particulate filters. The work described in this paper was sought to provide a valid diesel particulate filter (DPF) model for coupling with engine/vehicle models under the same toolbox. A comprehensive two-level modeling approach, including a lumped parameter model and a detailed 1-D 3-layer-kinetics model, has been proposed for modeling wall-flow diesel particulate filters. Both are capable of modeling virtually all aspects of filter performance in terms of deep-bed filtration, particulate matter loading and filter regeneration.