Yue Chuanfeng, Wang Jingbo, Li Xiangyuan
College of Chemical Engineering, Sichuan University Chengdu 610065 P. R. China
Engineering Research Center of Combustion and Cooling for Aerospace Power, Ministry of Education, Sichuan University Chengdu 610065 P. R. China.
RSC Adv. 2023 Feb 6;13(7):4590-4600. doi: 10.1039/d2ra06075b. eCollection 2023 Jan 31.
The effects of different one-dimensional laminar flames on the prediction of nitrogen oxide (NO ) emission in Sandia Flame D are numerically investigated using a flamelet method in the present work. In addition to the basic control variables of the mixture fraction and the reaction progress variable for chemistry tabulation in this combustion model, two additional variables of mixture fraction variance and enthalpy loss are added to the control variable space to improve prediction accuracy of the NO pollutant. The former variable of mixture fraction variance is used for the presumed probability density function integration, and the latter takes into account the non-adiabatic effect. Two flamelet libraries are generated based on the one-dimensional unstretched premixed flame and the one-dimensional counterflow diffusion flame, respectively. An additional transport equation for the mass fraction of nitrogen oxide (NO) is solved for improving prediction accuracy. The unsteady Reynolds-averaged Navier-Stokes (URANS) simulation results are compared and analyzed with experimental data. The simulation results show dependence on the type of laminar flame. In the four-dimensional control variable space, the results with steady unstretched premixed flame indicate great agreement on the predictions of temperature and NO field. The computational method proposed in the present work sheds light on the high-precision combustion numerical simulation of NO emission.
本文采用小火焰方法，对不同的一维层流火焰对桑迪亚火焰D中氮氧化物（NO ）排放预测的影响进行了数值研究。在该燃烧模型中，除了用于化学制表的混合分数和反应进度变量这两个基本控制变量外，还在控制变量空间中添加了混合分数方差和焓损失这两个额外变量，以提高对NO 污染物的预测精度。混合分数方差的前一个变量用于假定概率密度函数积分，后一个变量考虑了非绝热效应。分别基于一维无拉伸预混火焰和一维逆流扩散火焰生成了两个小火焰库。求解了一个关于氮氧化物（NO）质量分数的附加输运方程，以提高预测精度。将非定常雷诺平均纳维-斯托克斯（URANS）模拟结果与实验数据进行了比较和分析。模拟结果显示出对层流火焰类型的依赖性。在四维控制变量空间中，稳态无拉伸预混火焰的结果在温度和NO场预测方面显示出很好的一致性。本文提出的计算方法为NO 排放的高精度燃烧数值模拟提供了思路。
