Sooting behavior of ethanol droplet combustion at elevated pressures under microgravity conditions
Sooting behavior of ethanol droplet combustion at elevated pressures under microgravity conditions
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微重力条件下高压乙醇液滴燃烧的烟灰行为
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
R. Dobashi
中科院分区：
文献类型：
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作者：
Bradley D. Urban;K. Kroenlein;A. Kazakov;F. Dryer;Ahmet Yozgatligil;M. Choi;S. Manzello;K. Lee;R. Dobashi
液体乙醇作为一种扩大石油衍生资源的手段或作为燃料添加剂以减少火花点火发动机的一氧化碳排放而广泛用于实际燃料中。最近的研究还表明，乙醇和其他含氧化合物可以添加到柴油燃料中，以减少颗粒物的排放。在这一粗略的研究中，观察了乙醇小液滴在微重力环境中的燃烧，以研究在较高环境压力和各种氧指数下的扩散火焰特性，所有这些都以氮气作为稀释剂。在NASA格伦研究中心2.2秒落塔，游离乙醇液滴在液滴燃烧实验（DCE）装置中点燃，并收集背光和火焰视图数据以评估火焰位置和燃烧速率。在高于3atm的环境压力下观察到大量的炭黑。在日本微重力中心10秒（JAMIC）落轴与液滴燃烧（SEDC）装置中的烟灰效应进行的实验中，获得了显示乙醇液滴燃烧的球形烟灰壳的第一个数据。由于在一个容易获得的压力范围内的小变化的烟灰形成的强烈的敏感性，乙醇似乎是一个简单的液体燃料，适合于对球形扩散火焰的烟灰形成的影响的基础研究。研究结果影响了关于在高压实际燃烧室中通过向燃料中添加乙醇来减少颗粒物的机制的讨论。
Liquid ethanol is widely used in practical fuels as a means to extend petroleum-derived resources or as a fuel additive to reduce emissions of carbon monoxide from spark ignition engines. Recent research has also suggested that ethanol and other oxygenates could be added to diesel fuel to reduce particulate emissions. In this cursory study, the combustion of small ethanol droplets in microgravity environments was observed to investigate diffusion flame characteristics at higher ambient pressures and at various oxygen indices, all with nitrogen as the diluent species. At the NASA Glenn Research Center 2.2-second drop tower, free ethanol droplets were ignited in the Droplet Combustion Experiment (DCE) apparatus, and backlit and flame view data were collected to evaluate flame position and burning rate. Profuse sooting was noted above 3 atm ambient pressure. In experiments performed at the Japan Microgravity Center 10-second (JAMIC) drop shaft with Sooting Effects in Droplet Combustion (SEDC) apparatus, the first data that displayed a spherical sootshell for ethanol droplet combustion was obtained. Because of the strong sensitivity of soot formation to small changes in an easily accessible range of pressures, ethanol appears to be a simple liquid fuel suitable for fundamental studies of soot formation effects on spherical diffusion flames. The results impact discussions regarding the mechanism of particulate reduction by ethanol addition to fuels in high-pressure practical combustors.