光线偏折对激光测量火焰温度场干涉图的影响

The Effect of Light Deflection on Interference Pattern of Flame Temperature Field with Measured by Laser

以燃烧数值模拟所获得的层流乙稀扩散火焰的折射率和温度数据为基础,利用所获得的离散数据和折射率公式,得到了任意光线在火焰单一高度平面上圆域范围内前进的详细过程。分析了由于折射率不均匀造成的光线偏折对利用激光全息干涉法测量火焰温度场干涉图的影响;给出了不同平行光条数和不同离轴距离光线的偏移情况;对实验中激光穿过火焰区域后的高亮边界现象进行了讨论。计算和分析表明:利用该算法可以计算出任意光线前进的详细数据;不同平行光条数和不同离轴距离光的偏折效应不一样,离轴距离越大,光的偏折效应越明显;激光穿过火焰区域后的高亮边界现象是由于光的偏折造成的,为干涉图像处理中相位的提取提供了依据。

Based on the numerical simulation data including temperature and refractive index of laminar ethylene diffusion flame, the detailed forward process of any light in the flame height of a single domain-wide circular plane is obtained applying discrete data and refractive index formula. The effect of light deflection due to uneven refractive index on interference pattern of flame temperature field with measured by laser holographic interference is carried out. Light deflective quantity with different parallel light quantities and off-axis distance is obtained. Highlight boundary phenomenon after laser passing through flame area is discussed. The above calcula-tion and analysis indicate that light deflective quantity is different with different parallel light quantities and off-axis distance. The larg-er off-axis distance is, the more obvious light refractive effect is. Highlight boundary phenomenon after laser passing through flame re-gion is caused by light deflection,which providing a basis for phase extraction in interference patterns.