Term of Award

Fall 2023

Degree Name

Master of Science, Mechanical Engineering

Document Type and Release Option

Thesis (open access)

Copyright Statement / License for Reuse

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.


Department of Mechanical Engineering

Committee Chair

Valentin Soloiu

Committee Member 1

Marcel Ilie

Committee Member 2

Mosfequr Rahman


With the increase in availability, feedstocks, and properties of alternative fuels, compatibility issues emerge between current engine platforms often requiring a limit on the blend percentage of alternative fuel in conventional fuel or alteration to the engine platform. Two key metrics were identified, autoignition quality and lubrication characteristics, as vital for the proper function of a compression ignition engine, and if the blend of alternative fuels matches these two criteria for the diesel standard, then the resulting blend percentage can be considered as a viable alternative for complete replacement of conventional petroleum ULSD. Autoignition quality was matched using blends S-8, DCN 62, and IPK, DCN 26, with three blends labeled as B1, B2, and B3. A modified DCN equation was then derived for the F-T fuels based on measured ID, CD, and DCN. The results of which determined that a 60% S-8 and 40% IPK blend percentage match the DCN set point of 50 and denoted in the text as S1. The lubricity investigation found that a 3% of a biodiesel compound, methyl oleate, improved average friction force and wear scar depth to within 1% of ULSD. This final surrogate blend is denoted as S2 for the duration of this study. All researched neat fuels and blends were investigated in the CVCC for LTHR, NTC, HTHR, peak pressure ringing, and energy released and duration of each combustion region. The analysis of peak pressure ringing indicated an increase in combustion stability for S2 when compared to ULSD. The LTHR analysis revealed that S2 has a much longer NTC region when compared to ULSD despite its increase in DCN. Three representative fuels were chosen for further investigation in both dual combustion chamber indirect injection and common rail direct injection engine platforms: ULSD (baseline), S2, and IPK. In both engines, the combustion of S2 resulted in a reduction in ringing intensity, BSFC, NOx emissions, CO2 emissions. No significant differences were found in peak pressure, peak pressure rise rate, or combustion phasing between the combustion of S2 and the combustion of ULSD indicating its high viability as a functional drop-in fuel replacement.

Research Data and Supplementary Material