Ignition enhancement using repetitive nanosecond discharge (NSD) is studied in a stoichiometric hydrogen/air mixture. Numerical simulations are conducted for the homogeneous ignition process using code incorporating ZDPlasKin and CHEMKIN. The objective is to examine how the characteristics of the NSD affects the ignition delay time and why the NSD promotes a homogeneous ignition process. The influence of pulse number, discharge frequency, reduced electric field, total input energy and input energy per pulse on the ignition process is investigated. It is found that the characteristics of NSD have a significant impact on the ignition delay time. The ignition delay time changes non-monotonically with the reduced electric field, and it depends on both the total input energy and the input energy per pulse. Furthermore, it is shown that the ignition enhancement by NSD is mainly due to the kinetic effects while the thermal effects (Joule heat) are negligible. The ignition enhancement is mainly caused by radicals, especially H and O, produced by NSD. A reaction pathway analysis is conducted to identify the key elementary reactions involved in the ignition enhancement using NSD. The electron impact reactions and quenching reactions of excited species are found to help to produce H and O radicals and thereby promote the homogeneous ignition process.

在化学计量的氢气/空气混合物中研究了使用重复纳秒放电（NSD）的点火增强作用。使用包含ZDPlasKin和CHEMKIN的代码对均匀点火过程进行了数值模拟。目的是研究NSD的特性如何影响点火延迟时间以及NSD为何促进均匀点火过程。研究了脉冲数，放电频率，减小的电场，总输入能量和每个脉冲的输入能量对点火过程的影响。发现NSD的特性对点火延迟时间有显着影响。点火延迟时间随电场减小而非单调变化，它取决于总输入能量和每个脉冲的输入能量。此外，结果表明，NSD的点火增强主要归因于动力学效应，而热效应（焦耳热）可忽略不计。点火增强主要是由NSD产生的自由基，尤其是H和O引起的。进行了反应路径分析，以确定使用NSD增强点火的关键基本反应。发现激发物种的电子冲击反应和猝灭反应有助于产生H和O自由基，从而促进均匀点火过程。进行了反应路径分析，以确定使用NSD增强点火的关键基本反应。发现激发物种的电子冲击反应和猝灭反应有助于产生H和O自由基，从而促进均匀点火过程。进行了反应路径分析，以确定使用NSD增强点火的关键基本反应。发现激发物种的电子冲击反应和猝灭反应有助于产生H和O自由基，从而促进均匀点火过程。