Effect of Jet Ignition on the Flame Propagation Process of Premixed Compressed by Piston

喷气点火器被认为有很大的潜力点燃发动机气缸中非常稀薄的混合物。然而，这种增强的机制还不清楚，预计自由基的作用可能会导致发动机的爆震。本研究项目就是为了说明这一点。在第一年，使用快速加压机和LivenGood-Wu积分来验证效果。下一项是结果。1)首先获得活化能等速率常数。2)从压缩开始到冷火焰开始的速率方程的积分量(对应于LivenGood-Wu积分)在喷气点火的燃烧历史上与普通点火情况没有什么不同，即自由基对冷火焰的着火没有影响。3)出现卷积涡，点火似乎是从它开始的。第二年，对w…进行了同样的实验1)增加了径向效应，增大了等离子体射流能量，增大了射流喷嘴直径，但LivenGood-Wu积分与常规点火情况没有区别，即不考虑径向效应对冷火焰起始点的影响。2)发展了一种可以方便测量密闭腔内二维温度分布的电阻线CT方法。3)测量了卷曲涡的温度分布，但不是强分布，整体温度与实际温度有很好的近似关系。第一年的研究成果将在第三届亚太燃烧与能源利用国际研讨会上公布，第二年的研究成果将在9月9日召开的国际内燃学研讨会上公布。‘97.它们也将提交给JSME交易。

Jet igniters have been thought to have a big potential to ignite very lean mixtures in the engine cylinder. However the mechanism of the enhancement is not made clear and the radical's effect is anticipated that it might induce the engine knocking. This research project is done to make clear this point. In the first year, Rapid Compression Machine and Livengood-Wu integral was employed to prove the effect. Next items are the result.1) Rate constants like activation energy are obtained first. The accuracy is much better than those values presented in the previous repots.2) Integrated amount of rate equation (which corresponds Livengood-Wu integral) from the compression start to the cool flame onset along the combustion history of the jet ignition doesn't differ from that of normal ignition case, namely, the radical doesn't affected on the cool flame onset.3) There appears a roll-up vortex and the ignition seems to start from it.In the second year, the same experiment was performed for w … More ide range of jet condition, moreover the temperature distribution is measured using resistance wire CT which was developed by this research team.1) Radical effect was increased to make plasma jet energy bigger and to make jet nozzle diameter bigger, however the Livengood-Wu integral didn't differ from conventional ignition cases, namely, the radical effect on the cool flame onset was denied.2) Resistance wire CT method was developed to easily measure transient two dimensional temperature distribution in a closed chamber. It was applied to measure temperature distribution of roll-up vortex which was generated in the rapid compression machine.3) Temperature distribution of roll-up vortex was detected but is was not strong distribution and the bulk temperature was a good approximation for the real temperature.Results of first year were presented on the 3rd Asia-pacific International Symposium on Combustion and Energy Utilization and the results of second year are going to be presented on the symposium of internal combustion held by JSME in Sept. '97. They are also going to be submitted to JSME transactions. Less