Date of Award


Publication Type

Master Thesis

Degree Name



Mechanical, Automotive, and Materials Engineering


Applied sciences


Ming Zheng




Requirements to meet stringent nitrogen oxide emission regulations are forcing modern diesel engines to adopt low-temperature combustion modes. However, as emission control techniques such as exhaust gas recirculation are implemented to achieve low-temperature combustion, the resulting increase in partial-combustion products can be significant in quantity as pollutants and as sources of lost engine efficiency. This work examined the partial-combustion hydrocarbon species emitted in a research diesel engine operating under low-temperature combustion. The measurement of carbon related emissions were performed using: a flame-ionization detector for total hydrocarbons, a Fourier transform infrared spectrometer for speciation of key hydrocarbons, and non-dispersive infrared detectors for carbon monoxide and carbon dioxide. The quantity and composition of the hydrocarbon emissions with respect to engine load, exhaust gas recirculation rate, intake pressure, and fuel injection pressure were investigated. The results indicated that at low engine loads, heavier hydrocarbons were the dominant contributors to total emissions. At higher loads the shift toward emissions of lighter hydrocarbons, especially in the one to two carbon range, indicated more complete fuel breakdown but lack of complete oxidation.