Effect of Molecular Structure on Soot Formation Characteristics of Aviation Turbine Fuels

The smoke point is shown to be quantitatively related to the molecular structure of hydrocarbon fuels. A fast technique of determining molecular composition of commercial and experimental fuels, in terms of carbon type structure, by using a proton nuclear magnetic resonance ({sup 1}{ital H} {ital NMR}) spectrometry is described. By measuring the smoke point soot yields of a laminar diffusion flame with a group of fuels all having a constant hydrogen to carbon ratio it is shown that neither the smoke point nor hydrogen to carbon ratio alone can describe the sooting propensity of turbine fuels. Obtained results indicate that smoke point and hydrogen to carbon ratio are complementary to each other in describing the sooting propensities of turbine fuels. This is further tested using the available data in literature obtained from gas turbine combustors and diffusion flames.