利用飞秒激光成丝对丁烷燃烧进行诊断

发布时间：2018-04-03 19:46

本文选题：飞秒激光成丝　切入点：非线性特性　出处：《吉林大学》2017年硕士论文

【摘要】：飞秒激光在非线性介质中传输时,当克尔自聚焦和等离子散焦达到动态平衡时,就会形成等离子体细丝。在成丝过程中会发生诸多非线性效应,是研究者关注的焦点。因飞秒激光成丝时光强极高,足以将空气分子激发到高激发态,而处于高激发态的分子再次返回基态时,就会发射特征荧光,近年来,它逐渐成为科学界研究的热点课题。本论文将飞秒激光成丝应用到燃烧科学领域,提出了一种新的燃烧诊断技术,即飞秒激光成丝诱导荧光光谱技术,这项技术能够实现对多种燃烧中间产物的同时探测。在遥感以及提高燃料能量转化效率等方面都具有很大的实用价值。我们对飞秒激光脉冲作用于丁烷火焰成丝时产生的后向散射的荧光进行了探测,发现多种燃烧中间产物CN、CH、C_2以及N_2、N_2~+在火焰中的空间分布呈现出极大的差异,这一差异主要取决于气体温度(密度)的空间分布,同时,在丁烷燃烧过程中发生的一系列反应也会对其产生一定的影响。飞秒激光成丝诱导荧光技术不仅可以用于探测燃烧过程中的中间产物,实现对燃烧过程的诊断,还可以对空气中含有的可燃气体成分进行检测。
[Abstract]:Femtosecond laser pulses propagating in nonlinear media, when Kerr self focusing and defocusing plasma equilibrium, it will form the plasma filaments. Many nonlinear effects in the spinning process, is the focus of study. Because of strong femtosecond laser filamentation time high enough to air molecules excited to excited, and in molecular highly excited states once again return to the ground state, will emit characteristic fluorescence, in recent years, it has gradually become a hot research topic in the scientific community. This paper will be applied to femtosecond laser filamentation combustion science, put forward a new combustion diagnostic technique, namely femtosecond laser filamentation induced fluorescence spectroscopy technology, this technology can achieve detection of the intermediate products at the same time. A variety of combustion has great practical value in remote sensing and improve fuel energy conversion efficiency and so on. We make the femtosecond laser pulse For the production of butane flame during spinning of the backscattered fluorescence were detected, found a variety of combustion intermediates CN, CH, C_2 and N_2, showed a great difference in the distribution of flame space in N_2~+, this difference mainly depends on the gas temperature (density) distribution, at the same time, in a series of butane combustion the reaction occurs in the process will have some effects on the femtosecond laser filamentation induced fluorescence technique not only can be used for the detection of combustion intermediates in the process of implementation of the diagnosis of the combustion process, but also on the fuel gas composition detection can be contained in the air.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.21;TN249

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