Oxidation and decomposition chemistry of the n-pentanol esters pentyl nitrite and pentyl nitrate: A detailed kinetic modeling study

Energetic materials often contain functional groups with bonded nitrogen and oxygen atoms, such as organic nitrate or nitro components. Therefore, this work presents the development of a comprehensive chemical kinetic model for the oxidation of pentyl nitrite and pentyl nitrate, which is validated against ignition delay time (IDT) measurements from a shock tube (ST) and a rapid compression machine (RCM) over a wide range of conditions: temperatures from 530 K to 790 K, pressures of 4 - 40 bar, diluted and air-like, and stoichiometries of Phi = 0.44 - 1.74. The kinetic model development is based on the use of analogies to alkanes and alcohols for rate parameter estimation. Further novel reaction classes are included in the model to improve the chemistry for the target components. The model performs well on the validation targets considered as well as on literature ignition delay times for npentanol and n-pentane including mixtures with NOx. Rates of production analyses and A-factor sensitivities highlight the importance of NOx cycling reactions at intermediate species, show the differences in the oxidation of pentyl-nitrate and pentyl-nitrite, and underline the known significance of initial decomposition to 1-pentoxy and NOx. However, a further analysis developed on a single reaction submodel also shows a significant impact on radical chemistry, especially at high levels of bath gas concentrations in the initial mixture.