Author ORCID Identifier
Semester
Fall
Date of Graduation
2025
Document Type
Dissertation (Campus Access)
Degree Type
PhD
College
Statler College of Engineering and Mineral Resources
Department
Mechanical and Aerospace Engineering
Committee Chair
Hailin Li
Committee Member
V’yacheslav Akkerman
Committee Member
Scott Wayne
Committee Member
Cosmin Dumitrescu
Committee Member
Yuhe Tian
Abstract
The ever increasingly stringent emissions regulations require the development of high-performance diesel engines equipped with advanced aftertreatment (AT) systems. Heavy-duty (HD) diesel engines are dominant for on- and off-road transportation due to their durability, power output, and fuel efficiency. Modern HD diesel engines have become significantly complex in complying with future emissions regulations and customer requirements, through employing high-pressure common rail fuel injection systems, turbochargers, electronic control unit (ECU), and exhaust AT systems, which require extensive engine testing for their optimization. However, it is unfeasible to experimentally examine all possible scenarios. It is therefore of great interest to engine manufacturers to develop numerical simulation models capable of simulating the performance and exhaust emissions of HD diesel engines. One of the main challenges associated with such an approach is establishing the appropriate level of complexity while maintaining sufficient outcome accuracy.
This research is a stride in this direction and has developed an integrated system model capable of simulating the performance and exhaust emissions from a HD diesel engine integrated with an advanced AT system. The sub-models developed include the engine model and AT system component sub-models, such as diesel oxidation catalyst (DOC), diesel particulate filter (DPF), selective catalytic reduction (SCR), and urea injection model. This study developed two engine models: (1) an engine map model based on steady-state maps and capable of simulating the performance and engine-out emissions of a HD diesel engine operated under steady-state and transient conditions for a given engine calibration; (2) an artificial neural network (ANN) models based on machine learning (ML) techniques and engine test data, which is capable of predicting the variation in engine performance and emissions with changes in fuel injection strategy and other operating parameters, under both steady-state and transient operating conditions and including unseen transient cycles with respect to the trained ML model. A Navistar 2021 Model Year (MY) E39 HD diesel engine provided experimental data used to develop engine model and AT system components. The impact of engine speed, load, and fuel injection strategy on engine performance, combustion process, and exhaust emissions was experimentally measured and investigated. The engine model and sub-models that simulate the AT system components were integrated into GT-Suite software and then validated against experimental data, including steady-state operating conditions and transient operation cycles. After that, the model simulated exhaust emissions for different fuel injection strategies and transient cycles. Results showed that the model can predict NOx emissions within 10% of measured values under transient operation, which demonstrates that the modeling methodology approach presented in this work is a very capable tool for original equipment manufacturers (OEMs) to use in optimizing HD diesel engines equipped with an advanced AT system.
In addition, two novel AT system concepts were proposed to improve the emissions conversion efficiency towards meeting future Environmental Protection Agency (EPA) regulations. The new concepts were modeled and integrated into GT-Suite, and the adopted strategy focused on introducing close-coupled (cc) catalysts upstream of the main AT system, along with electric heating elements in various configurations. Based on the simulation results, the electric exhaust heating system, cc-DOC, and cc-SCR were recognized as effective approaches to significantly reduce tailpipe NOx emissions. As a result, a current HD diesel engine can meet the 2027 NOx emissions standard (i.e., 0.035 g/bhp-hr NOx emissions) just by adding such accessories, hence avoiding the usual and very time-consuming recalibration of the engine ECU.
Recommended Citation
Kutkut, Almoutazbellah Adnan, "AI-Assisted System Optimization of a Heavy-Duty Diesel Engine Integrated with an Advanced Exhaust Aftertreatment" (2025). Graduate Theses, Dissertations, and Problem Reports. 13095.
https://researchrepository.wvu.edu/etd/13095