Studies of Blowout of Turbulent Diffusion Flames

本文对射流火焰熄火机理和熄火附近反应区的形态进行了实验研究。 大型结构的动力学对熄火附近火焰的影响进行了研究。 采用同步粒子图像测速技术（PIV）和双脉冲平面激光诱导荧光（PLIF）测量了火焰区相对于燃料流的传播速率。 CH自由基的双脉冲PLIF图像提供了火焰前锋运动的信息，而PIV提供了燃烧区燃料速度的信息。 利用CH-PLIF对井喷附近燃烧区前缘的结构进行了评估。 针对各种流动条件和下游位置执行这样的可视化。 对甲烷、乙烯和丙烷等多种燃料的同向气流速度对火焰熄灭的影响进行了评估。 进一步的研究进行对比的预混合在近场提升火焰的流场，远场火焰的提升扩散火焰稳定和过渡到井喷的机制的重点。

CTS-9905786AbstractThis is an experimental investigation of the mechanisms of jet flame blowout and of the morphology of the reaction zone near blowout. The effects of the dynamics of large-scale structures on flames near blowout is examined. Measurements of the propagation rate of the flame zone relative to the fuel flow are made using simultaneous particle image velocimetry (PIV) and double-pulsed planar laser-induced fluorescence (PLIF). The double-pulsed PLIF images of the CH radical provide information on the motion of the flamefront, while PIV provides information on the fuel velocity in the combustion zone. Assessment of structures at the leading edge of the combustion zone near blowout is made using CH-PLIF. Such visualizations are performed for a variety of flow conditions and downstream positions. The effect of the air coflow velocity on flame blowout is assessed for a variety of fuels such as methane, ethylene, and propane. Further studies are performed to contrast premixedness in the flowfields in near-field lifted flames to far-field flames with an emphasis on the mechanism of lifted diffusion flame stabilization and the transition to blowout.