高压条件下平面火焰OH-PLIF实验研究

平面激光诱导荧光技术（planar laser-induced fluorescence，PLIF）是一种十分重要而且应用广泛的燃烧诊断技术，但是在实际发动机等高压环境开展OH-PLIF测量仍然具有挑战性.为了研究压强对OH-PLIF的影响，在自行设计的高压火焰炉上，搭建了一套OH-PLIF测量系统，选用A-X（1，0）电子跃迁带的P₁（1）激发谱线，在不同压强条件下对甲烷/空气预混平面火焰开展了OH-PLIF测量研究，同时对实验工况的荧光产额进行了仿真，并将仿真结果与实验结果进行了对比分析.研究结果表明，随着压强的增加，OH的荧光信号逐渐减弱，平面预混火焰的锋面厚度逐渐变薄，OH荧光信号的峰值位置会越来越靠近炉面，荧光淬灭效应在OH荧光强度-压强关系中起着决定性的作用. 

Planar Laser-Induced Fluorescence Measurements of OH on Flat Flames at High Pressures

Planar laser-induced fluorescence (PLIF) is one of the most important and widely-used laser diagnostic techniques in combustion studies. But it is still a challenge to apply OH-PLIF measurements in high-pressure combustion, such as practical engines. In order to study the effects of pressure on OH-PLIF, this paper presented OH-PLIF measurements of CH₄/air flat flames at high pressures. An OH-PLIF measurement set-up was established, and the measurements were carried out on a newly developed high-pressure burner. The fluorescence yields were numerically simulated under different combustion conditions in the experiment. The measurement results were analyzed and compared with the numerical simulation of fluorescence yield. It is found that the fluorescence decreases sharply as pressure increases. The peaks of fluorescence become closer to the burner exit at high pressures, because the thickness of flat flames becomes thinner when the pressure increases. According to the comparison between the experiment and simulation results, the fluorescence quenching effect is dominated in the pressure dependence of fluorescence.