Abstract
•Low temperature oxidation of n-hexane in a flow reactor.•Gas chromatography and laser diagnostics.•Kinetics modeling with detailed chemistry.
The risk of igniting a flammable mixture in fuel tank vapor space is a major concern in aviation safety. In order to analyze the hazards and develop mitigation strategies, it is necessary to characterize the explosive properties of kerosene vapor–air mixtures over wide ranges of initial conditions. n-Hexane has been extensively used in our laboratory as a single component surrogate of kerosene. In the present study, hexane oxidation by oxygen was studied in a flow reactor at equivalence ratios of 0.7, 1 and 1.5 for mixtures diluted at 90% with nitrogen. Residence time was set at 2s and the pressure at 100kPa. The evolution of the gas phase composition at the reactor exit was studied over the range 450–1000K. Laser-based diagnostics and gas chromatography analysis were used to characterize the exit mixture composition. The chemical species measurements revealed three distinct regimes of oxidation, namely (i) the cool flame region from 600 to 650K, (ii) the NTC region between 675 and 775K, and (iii) the high temperature oxidation regime from 800K. The modeling study demonstrated the capability of reproducing most of the trends observed experimentally.