Abstract

To study the role of the reactions of CH₃O₂ radicals in the unsteady process of formation and propagation of methane combustion waves in air at P = 1 atm, the reactions were mathematically simulated using a kinetic model complemented with a block of these reactions. The influence of this block is limited by the decomposition reaction СН₃О₂ → СН₃ + О₂(II); therefore, the standard calculations were performed for a wide range of compositions at a smaller value of the reaction rate constant k_2∞, and additional calculations were performed at a larger value of this constant. For mixtures containing 5, 9, and 16% CH₄, the calculations were performed without taking into account the CH₃O₂ radicals. All the calculated data (according to flame velocities and the structure of their preheating zones) were compared with one another and with the experimental values. Based on the results of standard calculations, the space profiles of temperature and substances were presented for mixtures containing 5, 9, and 16% CH₄, and time profiles were additionally given for the case with 9% CH₄. To characterize the structure of the combustion wave using these data, two small kinetic schemes were chosen, which are determined by the low-temperature kinetics of the HO₂ and CH₃O₂ radicals. Analytical criteria were obtained based on these schemes; the calculations of self-ignition temperatures using these criteria (including the state of various points of the preheating zone) characterize the change in the activity of the system up to its coldest point.

中文翻译：

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过氧化物在大气压力下甲烷-空气混合物燃烧波的冷区加热中的作用

摘要

为了研究CH ₃ O ₂自由基的反应在P = 1 atm的空气中甲烷燃烧波在空气中形成和传播的不稳定过程中的作用，使用动力学模型对这些反应进行了数学模拟，并补充了这些反应的一部分。该块的影响是由在分解反应限于СН ₃ О ₂ →СН ₃ +О ₂（II）; 因此，物在反应速率常数中的较小值对于宽范围的组合物的所执行的标准计算ķ _2∞，并在该常数的较大的值进行额外的计算。对于含5、9和16％CH的混合物_{如图4所示}，在不考虑CH ₃ O ₂自由基的情况下进行了计算。将所有计算的数据（根据火焰速度及其预热区的结构）相互比较并与实验值进行比较。根据标准计算的结果，给出了含5、9和16％CH _4的混合物的温度和物质的空间分布图，还给出了具有9％CH ₄的情况的时间分布图。为了使用这些数据来表征燃烧波的结构，选择了两个小的动力学方案，它们由HO ₂和CH ₃ O ₂的低温动力学确定。部首。基于这些方案获得了分析标准。利用这些标准（包括预热区各个点的状态）计算自燃温度，就可以表征系统活动至最冷点的变化。