A Comparative Experimental Study of the Autoignition Characteristics of Alternative and Conventional Jet Fuel/Oxidizer Mixtures
Authors: K. Kumar and C. J. Sung
Direct link to the paper: http://dx.doi.org/10.1016/j.fuel.2010.05.021
Autoignitioncharacteristics of an alternative (non-petroleum) and two conventionaljetfuels are investigated and compared using a heated rapid compression machine. The alternativejetfuel studied is known as “S-8”, which is a hydrocarbon mixture rich in C7–C18 linear and branched alkanes and is produced by Syntroleum via the Fischer–Tropsch process using synthesis gas derived from natural gas. Specifically, ignition delay times for S-8/oxidizermixtures are measured at compressed charge pressures corresponding to 7, 15, and 30 bar, in the low-to-intermediate temperature region ranging from 615 to 933 K, and for equivalence ratios varying from 0.43 to 2.29. For the conditions investigated for S-8, two-stage ignition response is observed. The negative temperature coefficient (NTC) behavior of the ignition delay time, typical of higher order hydrocarbons, is also noted. Further, the dependences of both the first-stage and the overall ignition delays on parameters such as pressure, temperature, and mixture composition are reported. A comparison between the autoignition responses obtained using S-8 and two petroleum-derived jetfuels, Jet-A and JP-8, is also conducted to establish an understanding of the relative reactivity of the three jetfuels. It is found that under the same operating conditions, while the three jetfuels share the common features of two-stage ignition characteristics and a NTC trend for ignition delays over a similar temperature range, S-8 has the shortest overall ignition delay times, followed by Jet-A and JP-8. The difference in ignition propensity signifies the effect of fuel composition and structure on autoignitioncharacteristics.
Citation: K. Kumar and C. J. Sung, “A Comparative Experimental Study of the Autoignition Characteristics of Alternative and Conventional Jet Fuel/Oxidizer Mixtures,” Fuel 89 (10), 2853-2863 (2010).