Flame structure in small-scale liquid film combustors
Flame structure in small-scale liquid film combustors
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DOI：
10.1016/j.proci.2006.08.030
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
T. Pham;D. Dunn-Rankin;W. Sirignano
中科院分区：
文献类型：
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作者：
T. Pham;D. Dunn-Rankin;W. Sirignano
用于商业、医疗、军事和政府应用的技术的最新进展增加了对便携式电力系统的需求。一种解决方案是设计一种小规模的液体燃料燃烧系统，该系统利用体积反应来快速释放能量，并利用非挥发性燃料来提供高比能。为了利用尺寸减小的高表面积与体积比（通常会增加热损失），一个创新概念是将燃料作为液膜喷射在内燃烧室表面上，通过将热量重新引导至膜蒸发来有效减少损失。该膜通过引入旋流气流在管状腔室中产生并稳定，并且对所产生的火焰的调查已经证明火焰点燃和稳定性取决于壁温和膜位置，并且不需要再循环或物理火焰稳定器。在低热导率石英燃烧室中研究火焰结构的尝试表明，壁面传热不良会影响火焰的稳定性。化学发光测量的OH的，CH的，和C2的强度，和阿贝尔变换的综合图像，以获得这些自由基物种的径向分布在蓝宝石室内支持的理论，即燃料膜火焰是由两种结构：在出口边缘的双火焰和中心三重火焰室内。
Recent advances in technology for commercial, medical, military, and governmental applications have increased the demand for portable power systems. One solution is to design a small-scale liquid-fueled combustion system, which takes advantage of volumetric reactions for quick energy release and a nonvolatile fuel that provides high specific energy. To make use of the high surface-to-volume ratios with decreasing size that generally increase heat loss, an innovative concept is to inject the fuel as a liquid film on the inner combustor surface, effectively reducing losses by redirecting heat towards film vaporization. This film is generated and stabilized in a tubular chamber by introducing swirling airflow, and investigation of the resulting flames has demonstrated that flame ignition and stability are dependent upon wall temperature and film location, and do not require recirculation or a physical flameholder. Attempts to investigate flame structures in a low thermal conductivity quartz chamber have revealed that poor wall heat transfer compromises the stability of the flame. Chemiluminescence measurements of the OH∗, CH∗, and C2∗intensities, and an Abel transform of the integrated images to obtain the radial distribution of these radical species within a sapphire chamber supports the theory that the fuel-film flame is composed of two structures: a double flame at the exit rim and a central triple flame within the chamber.