Extinction strain rates of n-butanol, 2-butanol and iso-butanol in counterflow non-premixed flamelets

butanol isomers;extinction strain rate;annular;edge flame

Mitsingas, Constandino ; Kyritsis ; Dimitrios C.

关键词: butanol isomers;    extinction strain rate;    annular;    edge flame;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/30996/Mitsingas_Constandinos.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The extinction strain rates of three butanol isomers, (n-butanol, sec-butanol and iso-butanol) were studied experimentally in a counterflow burner, and computationally using a one-dimensional numerical model. The experimental results provided an insight in how the difference between molecular structures affects combustion of the isomers. Molecular branching made the isomers more prone to extinction. They shared a similar maximum temperature, as well as virtually identical high temperature kinetics, which implied that the underlying chemistry that produced difference in extinction strain rates lay, in the low-temperature oxidation steps. A numerical study was employed to calculate the extinction strain rate of n-butanol, and compare it with the experimental results. Good correlation was observed between the simulation and experimental data. During gradual increase of strain that led to extinction in the computations, the maximum temperature as well as the reaction zone thickness decreased. The mole fractions of H and OH radicals decreased, while HCO appeared to remain constant throughout the process. The formation of an annular edge flame at high strain rates was also observed experimentally for all the isomers. Very rich mixtures (ϕ=4 or higher), produced more resilient edge flames, than lean (ϕ=0.5 or lower) ones.