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

人们一直认为，喷气点火器有很大的潜力点燃发动机气缸中非常稀薄的混合物。但其增强机理尚不清楚，预计自由基的作用可能引起发动机爆震。这个研究项目就是为了说明这一点。第一年用快速压缩机和livenggood - wu积分来证明效果。下一项是结果。1)首先得到活化能等速率常数。其准确性比以前报告中提供的值要好得多。2)从压缩开始到冷起焰的速率方程积分（对应livenggood - wu积分）沿燃烧历史与正常点火情况的积分没有差异，即自由基对冷起焰没有影响。3)出现了一个卷起的涡流，点火似乎是从它开始的。第二年进行了同样的实验，在更宽的射流条件范围内，使用本课题组研制的电阻丝CT测量了温度分布。1)增加自由基效应使等离子体射流能量更大，射流喷嘴直径更大，但Livengood-Wu积分与常规点火情况没有区别，即否定了自由基对冷火焰起燃的影响。2)开发了电阻丝CT法，方便测量密闭腔内瞬态二维温度分布。应用该方法对快速压缩机中产生的卷起涡温度分布进行了测量。3)检测到卷起涡的温度分布，但温度分布不强，体温较好地逼近了实际温度。第一年的研究结果将在第三届亚太燃烧与能源利用国际研讨会上发表，第二年的研究结果将在9月由JSME举办的内燃机研讨会上发表。97年。它们也将提交给JSME交易。少

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