航空学报 > 2023, Vol. 44 Issue (15): 528866-528866   doi: 10.7527/S1000-6893.2023.28866

流体力学与飞行器总体设计

微米级铝颗粒在水蒸气和氧气中的点火燃烧特性

胡泽君, 冯运超(), 何志成, 夏智勋, 李明泰   

  1. 国防科技大学 空天科学学院,长沙  410073
  • 收稿日期:2023-04-13 修回日期:2023-05-04 接受日期:2023-05-12 出版日期:2023-06-30 发布日期:2023-05-15
  • 通讯作者: 冯运超 E-mail:yunchaofeng@nudt.edu.cn
  • 基金资助:
    国家自然科学基金(52006240);湖南省自然科学基金(2021JJ30775)

Ignition and combustion characteristics of micro-sized aluminum particles in H2O and O2

Zejun HU, Yunchao FENG(), Zhicheng HE, Zhixun XIA, Mingtai LI   

  1. College of Aerospace Science and Technology,National University of Defense Technology,Changsha  410073,China
  • Received:2023-04-13 Revised:2023-05-04 Accepted:2023-05-12 Online:2023-06-30 Published:2023-05-15
  • Contact: Yunchao FENG E-mail:yunchaofeng@nudt.edu.cn
  • Supported by:
    National Natural Science Foundation of China(52006240);Hunan Provincial Natural Science Foundation(2021JJ30775)

摘要:

通过实验研究了单个微米级铝颗粒(50~160 μm)在水蒸气和不同氧含量环境中的点火燃烧特性,通过铝颗粒的光学信息确定了其初始直径和火焰平均直径,划分了点火延迟时间和燃烧时间。铝颗粒的燃烧过程会发生多种不同的燃烧行为,颗粒破碎、喷射更易发生在温度更高的环境中,微爆更易发生在氧含量更高的环境中。提高环境温度和含氧量均可以减少颗粒的点火延迟时间,但是温度更高反而使颗粒的燃烧时间更长,这可能是高温氧化铝带走了颗粒大量的热量造成的。提高氧含量可以有效减少颗粒的燃烧时间,在弱氧化性环境中铝颗粒的燃烧集中在表面,并且难以完全燃烧,表面反应在燃烧过程中发挥了重要的作用。

关键词: 铝颗粒, 微米级单颗粒, 点火燃烧, 水蒸气, 氧气

Abstract:

The ignition and combustion characteristics of single micro-sized aluminum particles (50-160 μm) in water vapor and different oxygen contents are studied experimentally. The initial diameters and flame average diameters of the aluminum particles are determined by their optical information, and the ignition delay time and combustion time are divided. Different combustion behaviors will occur in the combustion process of aluminum particles. Particle fragmentation and injection are more likely to occur in the environment with higher temperature, and micro-explosion is more prevalent in the environment with higher oxygen content. Increasing the ambient temperature or oxygen content can reduce the ignition delay time of the particles, but the higher temperature makes the combustion time of the particles longer, which may be caused by the high temperature alumina taking away a lot of heat. Increasing the oxygen content can effectively reduce the combustion time of the particles. In weak oxidation environment, the combustion of aluminum particles is concentrated on the surface, and is difficult to burn completely. The surface reaction plays an important role in the combustion process.

Key words: aluminum particles, micro-sized single particle, ignition and combustion, water vapor, oxygen

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