Date of Award
2026
Document Type
Open Access Dissertation
Degree Name
Doctor of Philosophy in Mechanical Engineering-Engineering Mechanics (PhD)
Administrative Home Department
Department of Mechanical and Aerospace Engineering
Advisor 1
Gordon Parker
Committee Member 1
John Johnson
Committee Member 2
Jeff Naber
Committee Member 3
Allan Struthers
Abstract
Diesel engine exhaust contains regulated species, including carbon monoxide, hydrocarbons, nitrogen oxides, and particulate matter (PM). Meeting increasingly stringent emission standards typically requires multiple aftertreatment components, motivating the development of multifunctional devices that reduce system size, cost, and catalyst usage. Computational models are essential for guiding this design process; however, existing models primarily focus on single-function devices and rarely capture the behavior of multifunctional systems with multiple catalyst washcoats. This work presents a physics-based model of a wall-flow diesel oxidation catalyst filter (DOCF), a multifunctional device that integrates the roles of a diesel oxidation catalyst and a diesel particulate filter using multiple catalyst washcoats. The model captures coupled gas state, reaction kinetics, PM filtration and oxidation, and thermal response. Particular emphasis is placed on NO2 production and mass transport, which are critical to PM oxidation. An object-oriented modeling framework with adaptive spatial discretization was used to couple the gas state, kinetics, mass transport, PM filtration and oxidation, and thermal response submodels. The model is calibrated using data from spatially resolved reactor experiments and full-scale engine tests, including inlet and outlet species measurements and internal temperature measurements. The results show that axial variations in catalyst properties and wall permeability strongly influence the distribution of NO2, important for PM oxidation. The model demonstrates strong agreement with both reactor and engine loading data, with low errors of outlet concentrations of Nitrous Oxide, Nitrogen Dioxide, Carbon Monoxide, and Hydrocarbons across all runs. This provides new insight into the role of washcoat distribution in governing device performance. This work establishes a modeling framework for multifunctional, multi-washcoat aftertreatment systems and provides a tool for optimizing catalyst placement and improving emissions performance in a next-generation diesel aftertreatment design.
Recommended Citation
Price, Thomas K., "DEVELOPMENT AND CALIBRATION OF A 2-D DIESEL OXIDATION CATALYST FILTER (DOCF) MODEL WITH SPATIALLY VARYING WASHCOATS USING SPACIMS AND ENGINE LOADING DATA", Open Access Dissertation, Michigan Technological University, 2026.