Numerical Simulation of the Effect of Additives on Autoignition of Lean Hydrogen–Air Mixtures

• Published in: Russian journal of physical chemistry. B 2023-04, Vol.17 (2), p.425-432
• Main Authors: Tereza, A. M., Agafonov, G. L., Anderzhanov, E. K., Betev, A. S., Medvedev, S. P., Khomik, S. V., Cherepanova, T. T.
• Format: Article
• Language: English
• Subjects: Additives; Chemistry; Chemistry and Materials Science; Combustion; Delay time; Explosion; High temperature; Hydrogen peroxide; Ignition; Initial pressure; Low temperature; Mixtures; Physical Chemistry; Shock Waves; Spontaneous combustion; Temperature; Temperature dependence
• ISSN: 1990-7931; 1990-7923
• DOI: 10.1134/S1990793123020173

Simulations of the effect of addition of atoms, molecules, and radicals on autoignition of lean (14%) and ultra-lean (6%) hydrogen–air mixtures are performed in the temperature range of 800 to 1700 K at initial pressures of 1 and 6 bar. Computed results demonstrate that adding H, O, OH, HO 2 , and H 2 O 2 reduces ignition delay time τ. Common tendencies are revealed in the temperature-dependent effects of the added species. For each additive, the corresponding effect is found to be the strongest at temperatures near 900 and 1100 K at pressures of 1 and 6 bar, respectively. It is shown that the effects of addition of O and H are similar in magnitude. The effect of НО 2 is much weaker compared to other additives, and its temperature dependence is qualitatively analogous to that of Н 2 О 2 . While the extent of ignition-delay reduction decreases towards the endpoints of the temperature interval explored for all additives, significant effects persist in its high-temperature part for OH and in the low-temperature one for HO 2 and H 2 O 2 . Addition of water up to 1% does not affect the value of τ.