Zhang Jiayao, Shaddix Christopher R, Schefer Robert W
Combustion Research Facility, Sandia National Laboratories, 7011 East Avenue, Livermore, California 94550, USA.
Rev Sci Instrum. 2011 Jul;82(7):074101. doi: 10.1063/1.3605491.
Experimental measurements in laboratory-scale turbulent burners with well-controlled boundary and flow configurations can provide valuable data for validating models of turbulence-chemistry interactions applicable to the design and analysis of practical combustors. This paper reports on the design of two canonical nonpremixed turbulent jet burners for use with undiluted gaseous and liquid hydrocarbon fuels, respectively. Previous burners of this type have only been developed for fuels composed of H(2), CO, and/or methane, often with substantial dilution. While both new burners are composed of concentric tubes with annular pilot flames, the liquid-fuel burner has an additional fuel vaporization step and an electrically heated fuel vapor delivery system. The performance of these burners is demonstrated by interrogating four ethylene flames and one flame fueled by a simple JP-8 surrogate. Through visual observation, it is found that the visible flame lengths show good agreement with standard empirical correlations. Rayleigh line imaging demonstrates that the pilot flame provides a spatially homogeneous flow of hot products along the edge of the fuel jet. Planar imaging of OH laser-induced fluorescence reveals a lack of local flame extinction in the high-strain near-burner region for fuel jet Reynolds numbers (Re) less than 20,000, and increasingly common extinction events for higher jet velocities. Planar imaging of soot laser-induced incandescence shows that the soot layers in these flames are relatively thin and are entrained into vortical flow structures in fuel-rich regions inside of the flame sheet.
在具有良好控制的边界和流动配置的实验室规模湍流燃烧器中进行的实验测量，可以为验证适用于实际燃烧器设计和分析的湍流-化学反应相互作用模型提供有价值的数据。本文分别报道了两种用于未稀释气态和液态烃燃料的典型非预混湍流射流燃烧器的设计。此前这类燃烧器仅针对由氢气、一氧化碳和/或甲烷组成的燃料开发，且通常有大量稀释。虽然这两种新燃烧器均由带有环形引导火焰的同心管组成，但液体燃料燃烧器还有一个额外的燃料汽化步骤和一个电加热的燃料蒸汽输送系统。通过对四个乙烯火焰和一个由简单JP - 8替代燃料燃烧的火焰进行研究，展示了这些燃烧器的性能。通过视觉观察发现，可见火焰长度与标准经验关联式吻合良好。瑞利线成像表明，引导火焰沿燃料射流边缘提供了热产物的空间均匀流动。OH激光诱导荧光的平面成像显示，对于燃料射流雷诺数（Re）小于20000的情况，在靠近燃烧器的高应变区域不存在局部火焰熄灭现象，而对于更高的射流速度，火焰熄灭事件越来越普遍。碳烟激光诱导白热发光的平面成像表明，这些火焰中的碳烟层相对较薄，并被卷入火焰片内富燃料区域的涡旋流动结构中。
