Direct Numerical Simulation of Complex Fuel Combustion with Detailed Chemistry: Physical Insight and Mean Reaction Rate Modeling
Direct Numerical Simulation of Complex Fuel Combustion with Detailed Chemistry: Physical Insight and Mean Reaction Rate Modeling
复制标题
复杂燃料燃烧的详细化学直接数值模拟：物理洞察和平均反应速率建模
DOI：
10.1080/00102202.2015.1064911
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发表时间：
2015
影响因子：
1.9
通讯作者：
N. Swaminathan
中科院分区：
文献类型：
--
作者：
Z. Nikolaou;N. Swaminathan
采用包含15种49种反应的骨架化学机理，对多组分燃料的自由传播预混火焰进行了直接数值模拟。燃料由CO、H2、H2O、CH4和CO2组成，其比例类似于高炉煤气或低热值合成气。为了阐明湍流对真实化学火焰的影响，模拟了低湍流水平和高湍流水平。发现多组分燃料火焰的结构比大多数普通火焰更为复杂，单个物种的反应区不一定相互重叠，并且具有较宽的放热区。物质质量分数和放热率表现出明显的离散性，其条件平均值与层流火焰结果保持接近。位移速度、拉伸率和曲率的概率密度函数是近高斯函数。在RANS环境下，使用这些DNS数据评估了五种不同的平均反应速率关闭，这可能是迄今为止最严格的燃烧模型测试。在测试模型的性能中观察到显著的数量差异，特别是在高湍流水平的情况下。
Direct numerical simulation (DNS) of freely-propagating premixed flames of a multi-component fuel is performed using a skeletal chemical mechanism with 49 reactions and 15 species. The fuel consists of CO, H2, H2O, CH4, and CO2 in proportions akin to blast furnace gas or a low calorific value syngas. The simulations include low and high turbulence levels to elucidate the effect of turbulence on realistic chemistry flames. The multi-component fuel flame is found to have a more complex structure than most common flames, with individual species’ reaction zones not necessarily overlapping with each other and with a wide heat releasing zone. The species mass fractions and heat release rate show significant scatter, with their conditional average however remaining close to the laminar flame result. Probability density functions of displacement speed, stretch rate, and curvature are near-Gaussian. Five different mean reaction rate closures are evaluated in the RANS context using these DNS data, presenting perhaps the most stringent test to date of the combustion models. Significant quantitative differences are observed in the performance of the models tested, especially for the higher turbulence level case.