Transient plasma ignition (TPI) employs highly non-equilibrium plasmas driven by nanosecond high-voltage pulses for combustion ignition. The effects of rise time and pulse repetition frequency (PRF) on combustion ignition are evaluated when transient plasmas, powered by 10-ns, kilovolt pulses, are employed to initiate combustion of lean, stoichiometric, or rich methane-dry air mixtures at atmospheric pressure. It was found that the plasmas driven by high voltage pulses with a faster rise time and PRF between 6–10 kHz enhanced combustion with higher peak pressure and/or shorter ignition delay. A mode transition in the plasma, corresponding to the combustion initiation, was observed based on voltage and current waveforms of four consecutive pulsed plasmas driven by a pulse burst at kilohertz PRFs. Although benefits in combustion ignition from a shorter rise time and optimal PRF were observed for all three equivalence mixture ratios, the highest peak pressure and shortest ignition delay were associated with the stoichiometric mixtures. In addition, the gas temperature of the transient plasma was measured by determining the rotational temperature of the 2nd positive system of nitrogen to be ∼1000 K for the first pulse and increased up to 2000 K after the application of the 4th pulse in a four-pulse burst TPI.

瞬态等离子体点火 (TPI) 采用由纳秒高压脉冲驱动的高度非平衡等离子体进行燃烧点火。当采用由 10 纳秒、千伏脉冲提供动力的瞬态等离子体在大气压下启动贫、化学计量或富甲烷-干燥空气混合物的燃烧时，评估上升时间和脉冲重复频率 (PRF) 对燃烧点火的影响. 发现由具有更快上升时间和 6-10 kHz 之间的 PRF 的高压脉冲驱动的等离子体以更高的峰值压力和/或更短的点火延迟增强燃烧。基于由千赫 PRF 脉冲突发驱动的四个连续脉冲等离子体的电压和电流波形，观察到等离子体中的模式转变，对应于燃烧的开始。尽管对于所有三个当量混合比都观察到来自较短上升时间和最佳 PRF 的燃烧点火的好处，但最高峰值压力和最短点火延迟与化学计量混合物相关。此外，通过确定第 2 个正氮系统的旋转温度对于第一个脉冲为 ~1000 K 并在第 4 个脉冲中施加第 4 个脉冲后增加到 2000 K 来测量瞬态等离子体的气体温度。脉冲突发 TPI。