Detonation inhibition using retardant weight analysis for halogenated compounds

The current study numerically evaluates the detonation inhibition effects of a range of halogenated compounds on hydrogen-air gaseous detonations. The halogenated compounds investigated in this research encompass halogen acids (HI, HBr, HCl, HF), halomethanes (\(\hbox {CH}_{{3}}\hbox {I}\), \(\hbox {CH}_{{3}}\hbox {Br}\), \(\hbox {CH}_{{3}}\hbox {Cl}\), \(\hbox {CH}_{{3}}\hbox {F}\)), haloethenes (\(\hbox {C}_{{2}}\hbox {H}_{{3}}\hbox {I}\), \(\hbox {C}_{{2}}\hbox {H}_{{3}}\hbox {Br}\), \(\hbox {C}_{{2}}\hbox {H}_{{3}}\hbox {Cl}\), \(\hbox {C}_{{2}}\hbox {H}_{{3}}\hbox {F}\)), haloethanes (\(\hbox {C}_{{2}}\hbox {H}_{{5}}\hbox {I}\), \(\hbox {C}_{{2}}\hbox {H}_{{5}}\hbox {Br}\), \(\hbox {C}_{{2}}\hbox {H}_{{5}}\hbox {Cl}\), \(\hbox {C}_{{2}}\hbox {H}_{{5}}\hbox {F}\)), and complex halogenated compounds (\(\hbox {CF}_{{3}}\hbox {I}\), \(\hbox {CF}_{{3}}\hbox {Br}\), \(\hbox {CF}_{{3}}\hbox {Cl}\), \(\hbox {CF}_{4}\)). The study employs a one-dimensional ZND model with detailed chemical kinetics to examine the impact on detonation propagation by adding these halogenated compounds to hydrogen-air mixtures. The effectiveness of these inhibitors is evaluated based on their capacity to increase the induction length, the amount of inhibitor needed to attenuate a detonation wave, and their influence on the detonability of the gaseous mixture under both lean and rich conditions. The results indicate that several halogenated compounds exhibit superior inhibition properties compared to Halon 1301 (\(\hbox {CF}_{{3}}\hbox {Br}\)). Specifically, \(\hbox {C}_{{2}}\hbox {H}_{{5}}\hbox {Br}\) leads to the most significant increase in the induction length, with HBr and \(\hbox {C}_{{2}}\hbox {H}_{{5}}\hbox {I}\) following closely, particularly at 20,000 ppmv concentration levels. However, it is worth noting that the inhibition efficiency also varies depending on the concentration of the inhibitor added to the gaseous \(\hbox {H}_{{2}}\)-air mixture. Moreover, based on retardant weight analysis, fluorinated compounds were found to be the most effective inhibitors, followed by chlorinated, brominated, and iodinated compounds across all categories of halogenated inhibitors.