Abstract High-frequency temperature measurements were carefully conducted for a 15 kW buoyant turbulent ethylene diffusion flame over a 15.2 cm diameter gas burner with air co-flow. A dual-thermocouple probe, consisting of two fine-wire thermocouples with 25 μ m and 50 μ m wire diameters, was used to determine a compensated turbulent gas temperature. A sensitivity analysis shows that temperatures resolved using this dual-thermocouple technique are less sensitive to changes in thermocouple bead size, therefore, uncertainty is greatly reduced even when soot deposition on the thermocouple bead occurs in sooty flames. Mean and root-mean square (rms) fluctuations of gas temperature were recorded in a two-dimensional plane across the flame centerline. The mean gas temperature monotonically decreases away from the flame centerline at most flame heights, except for 1 diameter above the burner, where a temperature dip is observed. The rms temperature peaks shift from the edge of the flame to the center as the height increases. This is due to the enhanced mixing between fuel and air, which is further shown using probability density functions of the local gas temperature. A systematic temperature dataset with high spatial resolution is established for sooty flames, which is valuable for future soot and radiation model validation.

中文翻译：

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使用双热电偶技术测量湍流漂浮乙烯扩散火焰的温度

摘要 对 15 kW 浮力湍流乙烯扩散火焰在 15.2 cm 直径的空气共流燃气燃烧器上仔细进行了高频温度测量。双热电偶探头由两个线径为 25 μm 和 50 μm 的细线热电偶组成，用于确定补偿湍流气体温度。灵敏度分析表明，使用这种双热电偶技术解析的温度对热电偶珠尺寸的变化不太敏感，因此，即使在煤烟火焰中热电偶珠上发生烟灰沉积时，不确定性也大大降低。气体温度的平均和均方根 (rms) 波动记录在跨越火焰中心线的二维平面中。在大多数火焰高度，平均气体温度远离火焰中心线单调下降，除了在燃烧器上方 1 个直径处观察到温度下降。随着高度的增加，均方根温度峰值从火焰边缘向中心移动。这是由于燃料和空气之间的混合增强，使用局部气体温度的概率密度函数进一步显示了这一点。为煤烟火焰建立了具有高空间分辨率的系统温度数据集，这对未来煤烟和辐射模型验证具有重要价值。