基于激光诱导偏振光谱与激光诱导荧光技术的CH4/AIR火焰参数测量

建立了激光诱导偏振光谱（LIPS）和激光诱导荧光（LIF）联合的燃烧流场诊断系统，测量了CH4/AIR预混火焰中心不同高度处的OH荧光光谱和激光诱导偏振光谱，计算了OH的浓度及燃烧场温度分布。分析了燃烧炉表面对荧光收集效率的影响，并对两种技术的测量数据进行了分析比对，获得了火焰中心OH密度的分布规律。实验结果表明，联合LIPS和LIF两种技术测量CH4/AIR预混火焰参数是可行的，两种技术测量结果的一致性较好，OH浓度的相对偏差小于5%，温度的相对偏差小于8%。

Measurement of CH4/AIR flame parameters by combination of laser induced polarization spectroscopy/laser induced fluorescence techniques

Laser induced polarization spectroscopy (LIPS) and laser induced fluorescence (LIF) measurement techniques have been employed simultaneously to diagnose CH4/AIR flame. Fluorescence spectra and polarization spectra of OH were measured at different height in the center of CH4/AIR flame at the same time, and the distributions of temperature and OH number density were obtained. The collection efficiency of fluorescence affected by the surface of the burner was analysed, the experimental data obtained by two techniques were compared, and OH number density distribution law along the height direction was acquired. The experimental results indicate the feasibility of combining these two techniques for combustion diagnostics, and the experimental data acquired by the two techniques agree well with each other, with a discrepancy within 5% for OH density and a discrepancy within 8% for temperature.