Optical diagnostics of nanosecond and nanometer ignition and quenching

纳秒和纳米点火和淬火的光学诊断

• 批准号: 16360105
• 负责人: TOMITA Eiji
• 金额: $ 9.79万
• 依托单位: Okayama University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16360105/
• 关键词: Laser ignition; Laser-induced plasma; Spectroscopy; Laminar premixed flame; Emission spectra

In order to obtain basic data for analysis of ignition mechanism, chemiluminescence was measured at the flame front and the anchor point of laminar premixed CH_4/air and C_3H_8/air flames. Using the chemiluminescence spectra, anchor point location, local equivalence ratio, and flame temperature were examined. The local equivalence ratio was measured using the intensity ratio of OH^* and CH^* and the temperature were using measured the intensity ratio of the P and the R branches of the OH^* spectra. The local equivalence ratio and the temperature were lower near the anchor point.When a powerful pulsed laser is focused to a small spot in gas, breakdown phenomena occurs and a spark plasma of high temperature and high pressure is created. If the laser beam interacts with a combustible gas, the plasma can ignite the gas. The emission spectra of the plasma were obtained by ICCD spectrometer and were captured using Framing ICCD camera. From these results, the following conclusions are obtained. (1)The shape of plasma turns out to be cylindrical at first. After that, the plasma expands spherically. The plasma size increases until 2000ns, after that time it was decreases rapidly. (2)The continuum spectrum by the bremsstrahlug and the recombination radiation came up at the earliest stage of the plasma development. Then the continuum spectrum decreased, the ionic spectra and the atomic spectra of hydrogen, nitrogen, oxygen, and carbon observed. (3)The plasma size was a correlated with the incident laser energy. The intensity ratios of H/O and H/N were found to be a liner function of equivalence ratio of the mixture. These results demonstrated that LIBS application can measure the local equivalence ratio of methane or propane premixed laminar flame.

为了获得点火机理分析的基础数据，对层流预混CH_4/空气和C_3H_8/空气火焰的火焰前锋和锚点进行了化学发光测量。使用化学发光光谱，检查锚点位置、局部当量比和火焰温度。使用 OH^* 和 CH^* 的强度比测量局部当量比，并使用测量 OH^* 光谱的 P 和 R 分支的强度比测量温度。锚点附近的局部当量比和温度较低。当强大的脉冲激光聚焦到气体中的一个小点时，会发生击穿现象并产生高温高压的火花等离子体。如果激光束与可燃气体相互作用，等离子体就会点燃该气体。等离子体的发射光谱由ICCD光谱仪获得，并使用分幅ICCD相机捕获。从这些结果可以得出以下结论。 (1)等离子体的形状最初是圆柱形的。之后，等离子体呈球形膨胀。等离子体尺寸增加直到2000ns，之后迅速减小。 (2)轫致辐射和复合辐射的连续谱在等离子体发展的最早阶段就出现了。然后连续谱下降，观察到氢、氮、氧、碳的离子谱和原子谱。 (3)等离子体尺寸与入射激光能量呈正相关。发现 H/O 和 H/N 的强度比是混合物当量比的线性函数。这些结果表明，LIBS 应用可以测量甲烷或丙烷预混层流火焰的局部当量比。

项目成果

Spatial and Temporal Characteristics of Laser-induced Air Plasma

激光诱导空气等离子体的时空特征

• 发表时间: 2006
• 期刊: 44th AiAA Aerospace Sciences Meeting and Exhibit 2006-1461
• 作者: Nobuyuki Kawahara;Eiji Tomita;Takashi Nakayama;Yuji Ikeda;Atsushi Nishiyama
• 通讯作者: Atsushi Nishiyama

Local equivalence ratio measurement of CH4/Air and C3H8/Air laminar Flames by Laser-Induced Breakdown Spectroscopy

激光诱导击穿光谱法测量 CH4/空气和 C3H8/空气层流火焰的局部当量比

• 发表时间: 2006
• 期刊: 44th AiAA Aerospace Sciences Meeting and Exhibit 2006-1465
• 作者: Yuji Ikeda;Atsushi Nishiyama;Nobuyuki Kawahara;Eiji Tomita;Takashi Nakayama
• 通讯作者: Takashi Nakayama

Local stoichiometry measurement of CH4/Air and C3H8/Air laminar flames by LIBS

利用 LIBS 对 CH4/Air 和 C3H8/Air 层流火焰进行局部化学计量测量

• 发表时间: 2005
• 期刊: Pacifichem 2005 871(CD-Rom)
• 作者: Yuji Ikeda;Atsushi Nishiyama;Nobuyuki Kawahara;Eiji Tomita;Takahiro Kurahashi
• 通讯作者: Takahiro Kurahashi

Measurement of Flame Propagation Characteristics in an SI Engine Using Micro-Local Chemiluminescence Technique

使用微局部化学发光技术测量 SI 发动机中的火焰传播特性

• 发表时间: 2005
• 期刊: SAR World Congress 2005-01-0645
• 作者: Nobuyuki Kawahara;Eiji Tomita;Akira Takeuchi;Shigeyuki Arimoto;Yuji Ikeda;Atsushi Nishiyama
• 通讯作者: Atsushi Nishiyama

In-spark-plug Sensor for analyzing the Initial Flame and Its Structure in an SI Engine

用于分析 SI 发动机中的初始火焰及其结构的火花塞内传感器

• 发表时间: 2005
• 期刊: SAR World Congress 2005-01-0644
• 作者: Yuji Ikeda;Atsushi Nishiyama;Nobuyuki Kawahara;Eiji Tomita;shigeyuki Arimoto;Akira takeuchi
• 通讯作者: Akira takeuchi