LES flamelet modeling of hydrogen combustion considering preferential diffusion effect
LES flamelet modeling of hydrogen combustion considering preferential diffusion effect
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DOI：
10.1016/j.ijhydene.2022.12.164
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发表时间：
2022-12
影响因子：
7.2
通讯作者：
R. Kai;Taiki Tokuoka;J. Nagao;A. Pillai;R. Kurose
中科院分区：
文献类型：
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作者：
R. Kai;Taiki Tokuoka;J. Nagao;A. Pillai;R. Kurose
采用一种显式考虑优先扩散效应的火焰面生成流形(FGM-PD)方法，对稀薄预混H2/空气低涡提升火焰进行了大涡模拟(LESS)，并与实验结果进行了比较。首先，通过对平面层流预混合H2/空气火焰的一维数值模拟，研究了FGM-PD方法的适用性。其次，采用FGM-PD和传统的FGM方法进行了较少的稀薄预混氢/空气低旋流提升火焰。一维数值模拟的结果表明，考虑优先扩散对准确预测火焰锋面附近的组分浓度具有重要意义。FGM-PD方法准确地预测了这一点，从而再现了层流燃烧速度以及温度和混合气分数的空间分布。三维大涡模拟结果证实，采用这种FGM-PD方法可以提高火焰锋面附近速度的预测精度。此外，FGM-PD方法预测的羟基质量分数分布呈现出先前实验中观察到的不均匀的指状结构。这种OH质量分数分布的不均匀性与FGM-PD方法预测的反应速率的不均匀相对应，对火焰前锋结构产生了强烈的影响。
A flamelet-generated manifold (FGM) method that explicitly considers the preferential diffusion effect, referred to as FGM-PD method, is employed for large-eddy simulations (LESs) of a lean-premixed H2/air low-swirl lifted flame, and the validity is examined by comparing with the experiment. First, the applicability of the FGM-PD method is investigated by one-dimensional numerical simulations of planar laminar premixed H2/air flames. Next, LESs of a lean-premixed H2/air low-swirl lifted flame are performed employing the FGM-PD and conventional FGM methods. Results of the one-dimensional numerical simulations show the importance of considering preferential diffusion to accurately predict species concentrations near the flame front. The FGM-PD method accurately predicts this, and therefore, reproduces the laminar burning velocity and spatial distributions of temperature and mixture fraction. Three-dimensional LES results confirm that the prediction accuracy of the velocities near the flame front is improved by employing this FGM-PD method. Additionally, the OH mass fraction distribution predicted by the FGM-PD method exhibits the inhomogeneous finger-like structure, which has been observed in previous experiments. This inhomogeneity of OH mass fraction distribution, which corresponds to that of the reaction rate, predicted by the FGM-PD method, strongly affects the flame front structure.