Low-temperature plasma (LTP) ignition concepts rely on the production of radical and charged species to speed up the onset of combustion in spark-ignition engines. These features are responsible for the superior performance of LTP igniters under extremely dilute combustion operation that is not achievable by conventional spark igniters. Additionally, LTP discharges extend the lifetime of the igniters, due to the avoidance of spark processes. For these reasons, the engine research community and the automotive industry have shown growing interest in this technology in the recent years. As of today, computational fluid-dynamics (CFD) codes typically used by the multi-dimensional engine modeling community do not have reliable models to describe LTP ignition processes. One key missing piece of information is the physical and chemical properties of the plasma and their effect on combustion ignition. Most non-equilibrium plasma simulations reported in literature are based on simplified, canonical geometries, with simple discharge excitation schemes. In this paper we conduct multi-dimensional modeling of the non-equilibrium plasma generated by an application-relevant radio-frequency (RF) corona discharge in air. Three test cases are simulated, characterized by different environmental pressure levels and peak electrode voltage values at room temperature. Streamer penetration, electron number density, atomic oxygen production, and bulk gas temperature distribution in the first 10 sinusoidal pulses are presented and discussed. This model can be used as a key tool for an in-depth understanding of RF-corona discharge for automotive applications and provides the basis for future implementations of dedicated LTP ignition models in CFD codes.

低温等离子体（LTP）点火概念依赖于自由基和带电物质的产生，以加速火花点火发动机中燃烧的开始。这些特性是LTP点火器在极其稀薄的燃烧操作下的卓越性能的原因，这是常规火花点火器无法实现的。另外，由于避免了火花过程，LTP放电延长了点火器的寿命。由于这些原因，近年来，发动机研究界和汽车行业对这种技术表现出了越来越高的兴趣。到目前为止，多维引擎建模社区通常使用的计算流体动力学（CFD）代码尚无可靠的模型来描述LTP点火过程。缺少的一项关键信息是等离子体的物理和化学性质及其对燃烧点火的影响。文献中报道的大多数非平衡等离子体模拟都是基于简化的规范几何结构以及简单的放电激发方案。在本文中，我们对空气中与应用相关的射频（RF）电晕放电产生的非平衡等离子体进行多维建模。模拟了三个测试用例，其特征在于不同的环境压力水平和室温下的峰值电极电压值。提出并讨论了在前10个正弦脉冲中的流光穿透力，电子数密度，原子氧产生和体气温度分布。