利用发射光谱测量技术分析了介质阻挡放电等离子体激励空气产生的主要活性粒子, 利用零维等离子体动力学模型模拟了甲烷/空气中放电阶段主要活性粒子的演化规律, 并通过敏感性与化学路径分析研究了O原子影响甲烷点火过程的化学动力学机理。研究表明: 空气中介质阻挡放电等离子体主要产生N2和O2的激发态粒子, 激发态粒子的数密度随着电压的增加而增大; 激发态粒子经过一系列物理化学反应最终转化成若干自由基, 其中O原子的摩尔分数最大; O原子缩短甲烷点火延迟时间一个量级, 原因在于添加O原子后甲基(CH3)的氧化途径由自点火过程中的经O2直接氧化为CH3O和CH2O转变为经HO2和O原子氧化为CH3O和CH2O, 由于后者的基元反应速率快, 因而明显缩短了点火延迟时间。

The main active particles produced by excitation of dielectric barrier discharge plasma on air were analyzed with emission spectrometry, the evolution rules of the active particles were simulated with plasma kinetic model, and the chemical kinetics mechanism of O-atom assisted ignition was revealed via sensitivity analysis and reaction path analysis. The results show that the main excited particles of N2 and O2 are generated with excitation of plasma on air, and the excited particles increase with the increase of voltage which will be to rapidly convert into free radicals and O-atom is the largest concentration of free radicals, and that the ignition delay time decreases about an order of magnitude, the oxidized pathway of CH3 changes to HO2 and O-atom from O2 for auto-ignition, and the latter reaction rate is much faster, that is why O-atom decreases the ignition delay time.