This study evaluates the ignition performance of a new miniaturised igniter that operates based on microwave resonance phenomenon. This igniter, named Flat Panel Igniter (FPI), consists of a flat ceramic panel with a metal strip inlay on the top surface acting as a resonance cavity. The FPI and a standard spark plug is used to ignite air–propane mixtures at various equivalence ratio inside a constant volume chamber. The results show that FPI requires much less ignition energy than spark plug at any given equivalence ratio. Furthermore, at the same energy, ignition with FPI results in a faster ignition delay and a shorter burnt duration. FPI ignition also allows for better lean limit as the ignition energy increases. Observation at non-reactive condition shows that the plasma from FPI is a lot larger than that of the spark plug, most likely due to the enhancement by MW energy. Via optical spectroscopy, FPI spectrum is also shown to be much more intense than the spark plug, with a higher level of OH* radicals and slightly higher temperature. Schlieren images of the combustion shows a more spherical appearance of the resulting flame, suggesting that the design of the FPI will induce less heat loss to the early flame kernel and hence facilitate faster flame growth. The igniters were also tested under the influence of cross flow by injecting an air stream across the plasma location. Due to its geometry the FPI plasma has a longer stretch distance compared to the spark discharge from spark plug and interestingly, the FPI does not suffer from blow-off even at high flow speed where spark plug suffers from very early blow-off and restrikes. Overall, the FPI has been shown to be a promising igniter that outperforms the traditional spark plug to enable further advancement in engine design.

这项研究评估了一种基于微波共振现象运行的新型小型点火器的点火性能。该点火器称为平板点火器（FPI），由一个平板陶瓷面板组成，该平板陶瓷面板的顶面上嵌有金属条，用作谐振腔。FPI和标准火花塞用于在恒定容积室内以各种当量比点燃空气-丙烷混合物。结果表明，在任何给定的当量比下，FPI所需要的点火能量都比火花塞少得多。此外，在相同能量下，使用FPI点火会导致更快的点火延迟和更短的燃烧持续时间。随着点火能量的增加，FPI点火还可以实现更好的稀薄极限。在非反应状态下的观察表明，来自FPI的等离子体比火花塞的等离子体大得多，最有可能是由于兆瓦能量的增加。通过光谱学，FPI光谱也显示出比火花塞更强的光谱，其中OH *自由基的含量更高，温度略高。燃烧的Schlieren图像显示了所产生火焰的球形外观，这表明FPI的设计将减少早期火焰核的热损失，从而促进更快的火焰生长。还通过在等离子位置注入空气流，在横流的影响下对点火器进行了测试。由于其几何形状，FPI等离子与火花塞的火花放电相比具有更长的伸展距离，而且有趣的是，即使在高流速下，FPI也不会遭受爆燃，而火花塞却遭受非常早的爆燃和重击。全面的，