Fundamental characteristics of laser breakdown assisted long distance discharge ignition
Fundamental characteristics of laser breakdown assisted long distance discharge ignition
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DOI：
10.1088/1361-6463/ab39af
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发表时间：
2019-09
期刊：
影响因子：
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通讯作者：
E. Takahashi;S. Sakamoto;O. Imamura;Y. Ohkuma;H. Yamasaki;H. Furutani;K. Akihama
中科院分区：
文献类型：
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作者：
E. Takahashi;S. Sakamoto;O. Imamura;Y. Ohkuma;H. Yamasaki;H. Furutani;K. Akihama
为了实现稀薄燃烧，人们开发了一种新的点火方法，称为激光击穿辅助远距离放电点火（LBALDI）。该方法有望通过长放电的产生来扩展初始火焰核，从而实现容积点火，从而改善稀燃极限。在这项研究中，LBALDI的基本特性，如燃料的长放电点火的影响进行了研究。传统的火花点火（SI）和LBALDI，其中电极距离分别为1 mm和8 mm，分别进行了比较，使用一个恒定的体积容器与基于纹影法的火焰成像的窗口。据确定，使用LBALDI的点火极限的延伸在贫丙烷和富甲烷预混合物中分别比在富丙烷和贫甲烷预混合物中更明显。这些组合对应于具有对于缺陷反应物大于1的刘易斯数的预混物。这种行为归因于LBALDI与SI相比产生大的初始等离子体。
Towards the realization of lean combustion, a new ignition method called laser breakdown-assisted long-distance discharge ignition (LBALDI) has been developed. This method is expected to realize volumetric ignition by extending the initial flame kernel via the generation of a long discharge, thereby improving the lean combustion limit. In this study, the fundamental characteristics of LBALDI such as the influence of fuel on the ignition of long discharge were investigated. Conventional spark ignition (SI) and LBALDI in which the electrode distances were 1 mm and 8 mm, respectively, were compared using a constant volume vessel with a window for flame imaging based on the schlieren method. It was determined that the extension in the ignition limit using LBALDI was more pronounced in a lean propane and rich methane premixture compared to a rich propane and lean methane premixture, respectively. These combinations correspond to premixtures with a Lewis number larger than unity for the deficient reactant. This behavior is attributed to the generation of large initial plasma for LBALDI compared to SI.