Development of a 1-D Catalyzed Diesel Particulate Filter Model for Simulation of the Oxidation of Particulate Matter and Gaseous Species During Passive Oxidation and Active Regeneration

Numerical modeling of aftertreatment systems has been proven to reduce development time as well as to facilitate understanding of the internal physical and chemical processes occurring during different operating conditions. Such a numerical model for a catalyzed diesel particulate filter (CPF) was developed in this research work which has been improved from an existing numerical model briefly described in reference.

The focus of this CPF model was to predict the effect of the catalyst on the gaseous species concentrations and to develop particulate matter (PM) filtration and oxidation models for the PM cake layer and substrate wall so as to develop an overall model that accurately predicts the pressure drop and PM oxidized during passive oxidation and active regeneration. Descriptions of the governing equations and corresponding numerical methods used with relevant boundary conditions are presented.

Calibration of the model was carried out using data obtained from passive oxidation as well as active regeneration experiments conducted on a Cummins ISL diesel engine using ultra-low sulfur diesel (ULSD) fuel with 10% (B10) and 20% (B20) bio-diesel blends and equipped with a diesel oxidation catalyst (DOC)-CPF aftertreatment system. Results obtained from simulations are presented to show the capability and variables that are obtainable from the model. This research work demonstrates the ability of the model to simulate performance characteristics of a DOC-CPF aftertreatment system at different engine operating conditions for varying rates of NO₂-assisted and O₂-assisted PM oxidation reactions for passive oxidation and active regeneration engine conditions.