Doctoral Dissertations


In order to develop design guidelines for optimum operations of internal combustion engines fueled with alternative fuels, a comprehensive understanding combustion behavior and the pollutant formation inside the cylinder are needed. The first part of this thesis aimed to numerically study the engine performance and in-cylinder pollutant formation in a spark ignition engine fueled with hydrogen. Advanced simulations were performed using multi- dimensional software AVL FIRE coupled with CHEMKIN. The detailed chemical reactions with 29 steps of hydrogen oxidation with additional nitrogen oxidation reactions were also employed. Formation rates of nitrogen oxides (NOx) within the engine were accurately predicted using the extended Zeldovich mechanism with parameters adjusted for a carbon-free fuel. The computational results were first validated against experimental results with different equivalence ratios and then employed to examine a spark-ignition engine fueled with hydrogen under different operating conditions. Strategies that could have significant effects on the engine performance and emissions, such as exhaust gas recirculation (EGR) and ignition timing were also investigated. Furthermore, the maximization of engine power and minimization of NOx emissions were considered as conflicting objectives for preliminary optimization. Finally, a skeletal reaction mechanism was developed to include the reaction kinetics of diesel and hydrogen fuel mixtures to investigate in-cylinder combustion processes of such a dual fuel compression-ignition engine. The model was then employed to examine the effects of exhaust gas recirculation (EGR) and N2 dilution on NOx emissions "--Abstract, page iii.


Köylü, Ümit Ö. (Ümit Özgür)

Committee Member(s)

Sheffield, John W.
Drallmeier, J. A.
Duan, Lian, 1983-
Sarangapani, Jagannathan, 1965-


Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering


Missouri University of Science and Technology

Publication Date

Summer 2015

Journal article titles appearing in thesis/dissertation

  • Computational investigation of in-cylinder combustion characteristics and emission of hydrogen IC engine using a 3D model with chemical kinetics
  • nfluence of ignition timing and EGR on the NOx emission and the performance of an SI engine fueled with hydrogen
  • Computational investigation of in-cylinder combustion characteristics and emission of hydrogen-diesel dual fuel engine using a 3D model with chemical kinetics
  • A computational study of in-cylinder NOx reduction strategies for a compression-ignition engine fueled with diesel/hydrogen mixtures


xii, 118 pages

Note about bibliography

Includes bibliographic references.


© 2015 Hassan A. Khairallah, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Subject Headings

Internal combustion engines -- Design -- Computer simulation
Hydrogen as fuel -- Testing
Spark ignition engines
Internal combustion engines -- Environmental aspects

Thesis Number

T 10758

Electronic OCLC #