Ignition delay-time behind reflected shock waves of small hydrocarbons–nitrous oxide(–oxygen) mixtures

Abstract

Although nitrous oxide has been identified as an important intermediate during the combustion of many solid propellants, there is a limited amount of data concerning the high-temperature oxidation of hydrocarbons by nitrous oxide. In the present study, ignition delay-times of small hydrocarbon-N 2 O mixtures with and without O 2 were investigated through shock-tube experiments and chemical kinetic simulations. Experimentally, it is shown that the addition of oxygen induces a significant reduction of the activation energy of the ignition process. Simulations demonstrate that delay-times are usually satisfactorilly predicted but that the detailed reaction models used do not capture all the features of the OH* emission profiles. Keywords Small hydrocarbons • Reflected shock wave • Ignition delay-time • Kinetic modeling Communicated by G. Ciccarelli.

Shock-induced ignition of methane sensitized by NO2 and N2O

“…For the high-pressure case around 27 atm (Fig. 3(c)), the results for the two levels of NO 2 concentration are very well reproduced by the model proposed in the present study, the model of Mével and Shepherd [13], and the model developed by Gersen et al [3]. At both conditions, the model of Sivaranakrishnan et al is too reactive compared to the data.…”

“…5(b)) conditions. The model of Mével and Shepherd [13] also reproduces the data with equally high accuracy. Predictions using this model are very close to the ones of the model proposed in the present study, although a bit less reactive (around a 25% difference) at high temperature for low-pressure conditions and slightly more reactive (around a 10% difference in ignition delay time) for pressures above 10 atm.…”

“…As mentioned earlier, the data presented in this study are compared to recent detailed kinetics models (Gersen et al [3], Sivaramakrishnan et al [8], and Mével and Shepherd [13]) from the literature. A model is also proposed in this study, assembled from the previous work from the present authors (NH 3 /H 2 /O 2 / NO 2 /N 2 O chemistry from Mathieu and Petersen [17], hydrocarbon chemistry from Metcalfe et al [18], and hydrocarbon/NOx interactions from Sivaramakrishnan et al [8]).…”

“…Several models from the recent literature were tested, namely the models from Gersen et al [3], Sivaramakrishnan et al [8], and Mével and Shepherd [13]. Whenever necessary, to allow for a comparison with the experimental data, these mechanisms were coupled with the OH ⁄ chemistry from Hall and Petersen [22].…”

“…The recent data from Mével and Shepherd [13] are also of interest since in addition to methane and ethane, fuels such as C 2 H 4 and C 2 H 2 were investigated with N 2 O(/O 2 ) as oxidizer(s). The model proposed in this study, along with the three other models selected, were tested against these data.…”