Term of Award

Spring 2020

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

Gustavo Molina

Committee Member 1

Valentin Soloiu

Committee Member 2

Aniruddha Mitra


Diesel fuel dilution is one of the many ways that new biofuels are tested for practical usability. The concern of this experimental work comes from the unique change in viscosity caused by mixing N-Butanol with ultra-low sulfur diesel (ULSD) fuel. The viscosity of the diesel decreases when mixed with the N-Butanol, this change in viscosity could cause increased wear rates and changes in the frictional force in the internal combustion engines in which they are used. The change in viscosity is much the same as when the diesel is mixed with other biodiesel alcohols but at a greater rate; in fact, the viscosity of the mixture is less than the viscosity of the N-Butanol alone but has a flatter slope in the viscosity vs temperature graph. Throughout the viscosity test, the samples are heated causing them to undergo a change in viscosity. The ULSD and ULSD-mixture test samples tend to eventually have a higher viscosity than N-Butanol over the life of the test despite starting at a lower viscosity at the beginning of the test. Research is presented here on the viscosity and tribometer-tested wear and lubricity of N-Butanol and of its mixtures in ultra-low sulfur diesel. The testing of N-Butanol as a lubricity additive follows the procedure outlined by Mozdzen (Mozdzen 1998). This includes tests of the degradation of fuel quality, change in lubricity (Wear and Friction), and crankcase lubricant interaction. The method of testing used a pin on disk tribometer to create wear tracts on test samples. These wear tracts were measured by weighing the samples before and after to determine the mass lost during the test. The friction force was directly measured by the tribometer’s built in force gauge. The tribometer is also outfitted with a force gauge used to measure the frictional force between the pin and disk. The different fuel mixtures were applied to the test sample to study their effects on the wear and friction. These tests found a maximum reduction of wear at 43% compared to pure USD when using a fuel blend of 25% N-Butanol and 75% ULSD. The 25% N-Butanol fuel blend also resulted in lower occurrences of Stick-and-Slip phenomena. Lastly the 25% N-Butanol fuel blend was tested for compatibility with the crankcase lubricant. The test resulted in the fuel blend being compatible with engine oil because of the absence of sediment in the test specimen. When the results are compared against the testing methods outlined by Mozdzen (Mozdzen 1998), N-Butanol passes the requirements to be a lubricity additive for ULSD.

Research Data and Supplementary Material


Supplimentary Data.xlsx (35352 kB)
combination of wear and friction data in one file

wear.xlsx (33 kB)

Available for download on Monday, April 14, 2025

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