一维湍流模型对He平面羽流和CH_4/H_2/N_2射流火焰的数值模拟

Simulation of He Plumes and CH_4/H_2/N_2Flames With One Dimensional Turbulence Model

本文采用一维湍流模型(ODT)对氦气平面羽流和CH_4/H_2/N_2射流火焰进行数值模拟,和前人的实验结果进行定量地对比。结果表明,ODT模型能够准确地预测平面羽流基本特征,湍流涡团的分布同流场拉伸率之间具有密切的关系,涡团强度的分布能够直观地表明当地的湍流强度。ODT模型埘CH_4/H_2/N_2瞬态火焰的模拟定性反应了火焰特性及其与湍流作用的规律,对温度-混合分数的预测值和实测值进行比较,发现甲烷火焰燃烧在富燃料侧并未达到平衡状态,因而基元反应对火焰特性的预测具有重要作用。

In this paper, a He plane plume and CH4/H2/N2 jet flame are simulated with the One-Dimensional Turbulence （ODT） model. The predicted results are quantitatively compared with the experimental data. The results show that ODT simulation can correctly predicted the flow field of the He plane plume. The distribution of the turbulent eddies has a close relationship with the strain rate, and the eddy intensity indicates the local turbulence intensity. The simulation results of instantaneous CH4/H2/N2 flames based on ODT can qualitatively reveals the flame characteristics and its interaction with turbulence. The comparison between ODT prediction and the measured temperature-mixture fraction shows that the reaction doesn＇t reach equilibrium at the fuel-rich side. The detailed reactions mechanism shall be considered in order to acquire a correct result.