Large Eddy Simulation of flame edge evolution in a spark-ignited methane-air jet
Large Eddy Simulation of flame edge evolution in a spark-ignited methane-air jet
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DOI：
10.1016/j.proci.2016.06.023
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Zhi X. Chen;Shaohong Ruan;N. Swaminathan
中科院分区：
文献类型：
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作者：
Zhi X. Chen;Shaohong Ruan;N. Swaminathan
采用大涡模拟（LES）方法对火花点火后甲烷-空气提升射流火焰的非定常演化过程进行了数值模拟。一个假定的联合概率密度函数（PDF）的方法是用于子网格燃烧建模占预混和非预混模式的贡献。两个火焰，一个与高，另一个与低的射流速度进行了研究，计算的火焰引导点的时间变化与测量数据的瞬态演化和最终的抬离高度吻合得很好。轴向和径向稳定位置的联合PDF表明，这些位置与射流出口速度相关。火焰引导点在三维物理空间中的演变使用其轨迹可视化，从点火位置开始到最终升空高度。观察到的两种速度的情况下，显示不同的火焰传播行为在不同的高度从射流出口的螺旋形路径。这些观察是在物理基础上解释的。
The unsteady evolution of lifted methane–air jet flames following spark ignition is computed using Large Eddy Simulation (LES). A presumed joint Probability Density Function (PDF) approach is used for the sub-grid combustion modelling accounting for both premixed and non-premixed mode contributions. Two flames, one with high and another with low jet velocities are investigated and the computed temporal variation of flame leading point agrees quite well with the measured data for both the transient evolution and final lift-off height. The joint PDF of the axial and radial stabilisation locations shows that these locations are correlated with the jet exit velocity. The flame leading point evolution in the three-dimensional physical space is visualised using its trajectory, starting from the ignition location to the final lift-off height. Aspiral-shaped path is observed for both velocity cases showing different flame propagation behaviours at different heights from the jet exit. These observations are explained on a physical basis.