【摘要】 对电火花引燃可燃气流的问题进行了理论分析和实验研究。将电火花看作是可燃气流中的一个线热源,运用边界层方程,考察反应区的发展,以其能否扩展开去作为引燃的判据,分析讨论了着火临界条件,导出了点火能和流速等参数之间的关系。实验中拍摄了不同条件下火焰发展的面貌,与数值计算得到的反应区发展相比较,表明这种模型确是在一定程度上反映了电火花引燃可燃气流的实际情况。此外,利用汽车发动机点火系统测试了电火花能量、来流速度、电极距离等因素对汽油-空气预混气的着火稀限的影响。更多还原

【Abstract】 The ignition of combustible gas stream by electric spark discharge was considered both theoretically and experimentally. By treating the spark as a linear heat source and applying the boundary layer assumptions, the development of the reaction zone was calculated. By adopting the ignition criterion based on the behaviour of the reaction zone development, the critical ignition condition was determined and discussed. The process of ignition was experimentally followed photographic inspections. Comparing with the computed reaction zone development, it shows that this sort of treatment do describes the essential feature of the ignition process. In addition, the influence of the spark energy, the gas stream speed and the electrode distance on the lean ignition limit of the gasoline-air mixtures by an automobile ignition coil was determined.更多还原