Date of Graduation


Document Type


Degree Type



Statler College of Engineering and Mineral Resources


Mechanical and Aerospace Engineering

Committee Chair

Gregory J. Thompson.


Heavy-duty diesel engines (HDDE) are the dominate prime movers of goods and services in the United States (US) and the world today. HDDE will continue to lead the transportation sector in the near term because of its superior fuel economy and performance compared to existing alternatives. However, HDDE produce many harmful emissions constituents that include: hydrocarbons (HC), oxides of nitrogen (NOx), carbon monoxide (CO), and particulate matter (PM). Due to these harmful emissions, the US Environmental Protection Agency (EPA) has been entrusted to enforce the Clean Air Act to limit the amount of emissions that can be produced from these HDDE. Additionally, the EPA requires that each state maintain a state implantation plan (SIP) to ensure minimum air quality standards. Because of SIP concerns, California and Texas have identified on-road heavy-duty diesel engines as a significant pollution source and have implemented an alternative diesel fuel formulation program in order to meet their SIP. To meet these more stringent fuel requirements, refineries use additives in diesel fuel to reduce these emissions. One main concern is when reducing these emissions using fuel additives, PM may be increased. PM is composed of soluble organics along with other constituents. The soluble organic fraction (SOF) contains polynuclear (or polycyclic) aromatic hydrocarbons (PAH) and nitro-PAHs (nitrogen-bound PAH) that are carcinogens and linked to heart and respiratory diseases. Because of this, California has required that the SOF emissions from HDDE fueled with on-road fuels sold in the state of California must not increase SOF more than 6% above a 48 cetane, 10% aromatic reference fuel SOF emissions values.;The purpose of this research was to develop a test procedure for SOF determination and quantifying the variability when using Soxhlet extraction. This was accomplished by extracting SOF from PM gathered from engines exercised over an engine dynamometer transient test cycle using various fuels. Also, the filter media, loaded and unloaded with PM, was examined to understand weighing variations over time in a controlled environment. Lastly, handling issues with the transportation of the filter media was examined.;The test procedure developed for SOF determination produced a coefficient of variation of 4.3%. Weighing variations were found to be caused from constituents lost by the filter media during the extraction process. However, some of this weight loss was then regained while the filter was conditioning in a conditioned clean room. This weight gain can be expressed using the equation: Wgain =.001175(thours0.74014). Lastly, shipping and receiving of filter media caused slight weight loss of initial weighing before extraction but had no affect on weight gain after extraction.