The streamer-to-spark transition in a point-to-plane configuration in atmospheric pressure air is studied using a 2D-0D combined approach. A validated fluid code is used and improved to model the spark stage. 2D modeling of discharges at three different temperatures 300, 600 and 800 K are conducted, the spark transition occurs when temperature reaches 800 K in the first pulse. A conservative criteria of spark transition temperature is proposed based on analytical solution and compared with experiments. Kinetics modeling of post discharge stage is conducted with consistent input values extracted from the 2D model. Results show that the streamer-to-spark transition can be initiated at a lower temperature (600 K) and lower field (50~75 Td), the long-lifetime O-atoms formed in previous pulses play an important role in "knocking off" the electrons from negative charged species and maintaining the electron density in the post discharge stage. The dominating process for electron production are electron detachment reactions from O3 -, O2 -, O-. The ionizations from excited species only accelerate the production of electrons when the plasma is already dense.

中文翻译：

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第一个脉冲和后放电阶段流注到火花转换的建模

使用 2D-0D 组合方法研究了大气压力空气中点到平面配置中的流光到火花的转变。使用并改进了经过验证的流体代码来模拟火花阶段。在三个不同温度 300、600 和 800 K 下进行放电的二维建模，当温度在第一个脉冲中达到 800 K 时发生火花转变。根据解析解，并与实验比较，提出了火花转变温度的保守判据。放电后阶段的动力学建模是使用从 2D 模型中提取的一致输入值进行的。结果表明，流光到火花的转变可以在较低的温度（600 K）和较低的场（50~75 Td）下启动，先前脉冲中形成的长寿命 O 原子在“敲除”过程中起重要作用。 ” 带负电物质的电子并在放电后阶段保持电子密度。电子产生的主要过程是来自 O3 -、O2 -、O- 的电子脱离反应。当等离子体已经很稠密时，激发物种的电离只会加速电子的产生。