The paper presents results demonstrating the application of filtered Rayleigh scattering (FRS) for quantitative temperature measurements within turbulent non-premixed jet flames. Through targeted fuel tailoring, i.e., the selection of a specific fuel mixture, temperature measurements are made under non-premixed fueling conditions with a single FRS measurement. For this to be feasible, the instantaneous measured FRS signal is uniquely proportional to the local temperature for all thermo-chemical states of the targeted fuel-oxidizer system. Simulated results using laminar, counterflow flame calculations show that for select CH4/H-2/Ar fuel mixtures issuing into air, a unique relationship between the local FRS signal and temperature is achieved for all mixture fraction values over a full range of operating conditions from near-equilibrium to near-extinction flames. Furthermore, for the selected FRS-optimized fuel, the local mixture-averaged Rayleigh scattering cross section is nearly constant from fuel to oxidizer to products. Thus, traditional laser Rayleigh scattering (LRS) can be used to determine the temperature as a "standard" to which to compare and assess the FRS-based temperature results. Simultaneous LRS-FRS temperature measurements from Re = 10,000, 20,000, and 30,000 turbulent non-premixed jet flames are presented that show good agreement between the two techniques in terms of instantaneous temperature fields and statistical quantities at various spatial locations within the flame. These results provide confidence that the current approach of FRS thermometry allows for accurate temperature measurements within the selected set of turbulent non-premixed flames. (C) 2019 Optical Society of America
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机译：本文提出了越来越多的未预混合喷射火焰中的过滤瑞利散射（FRS）在湍流中的定量温度测量的应用。通过靶向燃料剪裁，即，选择特定燃料混合物，在具有单个FRS测量的非预混燃料条件下进行温度测量。因此，可行的是，瞬时测量的FRS信号与靶向燃料氧化剂系统的所有热化学状态的局部温度唯一成比例。使用层流的模拟结果，逆流火焰计算表明，对于在空气中选择CH4 / H-2 / AR燃料混合物，局部FRS信号与温度之间的独特关系对于来自全方位的操作条件的所有混合分数值。近均衡到近消光火焰。此外，对于所选择的FRS优化的燃料，局部混合平均瑞利散射横截面几乎恒定地从燃料到氧化剂到产品。因此，传统的激光瑞利散射（LRS）可用于将温度确定为比较和评估基于FRS的温度结果的“标准”。 RE = 10,000,20,000和30,000个湍流未预混喷射火焰的同时LRS-FRS温度测量结果显示，在瞬时温度场和火焰中的各个空间位置处的统计量之间的两种技术之间存在良好的一致性。这些结果提供了令人信心，即FRS温度测量的电流方法允许精确的温度测量在所选湍流非预混火焰中。 （c）2019年光学学会
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