Modeling and Simultaneous Measurement of Local Concentration of Soot and Aromatic Carbon Concentration and Temperature

采用激光诱导发光（LII）、时间分辨激光诱导发光（TIRE-LII）和激光干涉成像测量液滴尺寸（ILIDS）技术研究了层流逆流稳定喷雾火焰中碳烟的形成过程。三个数量的烟灰，烟灰体积分数，烟灰颗粒尺寸，和烟灰数密度在火焰中可访问的LII和TIRE-LII方法。二维碳烟体积分数分布采用LII法测量，二维碳烟一次粒径分布采用TIRE-LII法测量。TIRE-LII方法的基本思想是在碳烟颗粒冷却期间的两个不同时刻测量白炽信号并计算信号强度比。此外，碳烟数密度计算从碳烟体积分数和碳烟颗粒尺寸测量LII和TIRE-LII方法，分别。在喷雾燃烧中，火焰的形成受液滴尺寸的影响 关于我们 喷雾分布，采用振动孔板雾化器控制喷雾特性。随着液滴平均粒径的增大，LII碳烟产生的频率增加，且在许多情况下，喷雾火焰中碳烟浓度的空间分布呈环形，火焰外侧区域的碳烟初始粒径大于火焰中心区域。相反，碳烟数密度在火焰中心区域周围比在火焰外部区域周围高。这表明烟灰主要在火焰的中心区域周围形成，并且烟灰随着其被输送到外部区域而增长。为了了解喷雾火焰中碳烟的形成过程，同时应用ILIDS和LII技术研究了喷雾液滴空间分布与碳烟浓度的关系。采用ILIDS方法将散焦图像压缩成线性干涉图，得到液滴特征的空间信息。研究发现，液滴尺寸越大，液滴越靠近低位燃烧器，即大液滴在获得足够的热量后才会汽化。火焰中心区域的未燃液滴吸收周围的热量或使周围处于富油状态，形成了碳烟浓度的内腔。少

Laser Induced Incandescence (LII), Time-Resolved Laser Induced Incandescence (TIRE-LII) and Interferometric Laser Imaging Droplet Sizing (ILIDS) were applied to investigate soot formation process in a spray flame stabilized in laminar counter-flow field. Three quantities of soot, soot volume fraction, soot particle sizes, and soot number density in the flame were accessible by LII and TIRE-LII methods. The distribution of two-dimensional soot volume fractions was measured by LII method, and the distribution of two-dimensional soot primary particle sizes was measured by TIRE-LII method. The basic idea of TIRE-LII method is to measure the incandescence signal at two different timing during the cooling of the soot particles and to calculate a signal intensity ratio. In addition, soot number density was calculated from soot volume fraction and soot particle size measured by LII and TIRE-LII methods, respectively. In the spray combustion, the flame formation is affected by the droplet size … More distribution of spray, we control the spray characteristics by the vibratory orifice atomizer. The frequency of LII soot production is increased as the mean droplet size is larger, and in the many cases, spatial distribution of soot concentration in the spray flame were ring-shaped with inner cavity and the soot primary size was larger around the outside region of the flame than around the center region of the flame. To the contrary, the soot number density was higher around the center region of the flame than around the outside region of the flame. This indicates that soot is formed mainly around the center region of a flame and soot grows up as it is conveyed to outside region. ILIDS and LII techniques were simultaneously applied to study the relation between spatial distribution of spray droplet and soot concentration in order to understand soot formation process in the spray flame. ILIDS method was used to get spatial information of the droplet characteristics by compressing defocus image into liner interferogram. It is found that the larger the droplets size is, the nearer the droplets fall to low burner, that is the large droplets don't vapor until they get enough heat. And the inner cavity of soot concentration was resulted from unburned droplets that exist in the center region of the flame due to absorbing the heat around them or making fuel-rich condition around them. Less