自发喇曼散射技术对燃烧场的诊断

Spontaneous Raman scattering diagnostics of combustion

介绍了利用NdYAG激光的三倍频激发自发振动喇曼散射技术对燃烧场的诊断及相关的实验原理,测量了不同配比条件下的CH4air预混火焰内的主要组分(N2,O2,H2O,CH4)及其相对浓度;并分别用分子浓度测温法和斯托克斯谱与反斯托克斯谱强度比法测量了火焰的温度;还对该技术测温、测浓度的不确定度进行了分析。将该技术应用到对复杂的固体燃剂燃烧场的诊断,取得了燃烧场中几种主要燃烧组分(N2,H2CO,CH4,H2O)的喇曼光谱,以及这些组分在燃烧过程中的变化信息。

Nd:YAG laser is used as a spontaneous vibrational Raman scattering (SVRS) source in combustion diagnostics. Multiple species data are acquired from both mathane-air combustion and solid fuel combustion. Spatially resolved Raman scattering spectra are used to measure concentrations of all major species (N_2, O_2, H_2O, CH_4) in methane-air flames with different ratio of CH_4 and air. Temperature of the flame is calculated by measuring the concentrations of all major species in flames, also by measureing the ratio of Stokes spectrum intensity and anti-Stokes spectrum intensity. Uncertainty of concentrations and temperature data is analysed, too. Moreover, the technique is used to diagnose solid fuel combustion with single-pulse. The Raman spectra of major species(N_2, H_2CO, CH_4, H_2O)at different moments during burning are acquired.