The Turbulent Flame Speed of Premixed Spherically Expanding Flames
The Turbulent Flame Speed of Premixed Spherically Expanding Flames
复制标题
预混球形膨胀火焰的湍流火焰速度
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
A. Tomboulides
中科院分区：
文献类型：
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作者：
G. Giannakopoulos;C. Frouzakis;M. Matalon;A. Tomboulides
采用大尺度直接数值模拟方法，研究了合成气/空气预混火焰在湍流流场中的膨胀过程。参数分析是在圆形和球形几何形状的火焰前锋和湍流场之间的相互作用的详细调查。本文研究了在内燃机条件下，合成气与空气的化学计量比（{ CO}/H_2=3）。讨论了积分放热率对流场特征（积分长度尺度和湍流强度）的依赖关系。重要的全球火焰量的长期演变进行了分析，并确定的机制，占主导地位的火焰核的增长。基于火焰表面积的变化率，推导了湍流预混球形火焰速度的表达式。
Premixed syngas/air flames expanding in turbulent flow fields are investigated using large scale direct numerical simulations. A parametric analysis is performed in circular and spherical geometries for the detailed investigation of the interaction between the flame front and the turbulent flow field. A stoichiometric syngas-air mixture with molar ratio ({ CO}/H_2=3) is considered at conditions relevant to internal combustion engines. The dependence of the integral heat release rate on the characteristics of the flow field (integral length scale and turbulent intensity) is discussed. The long-term evolution of important global flame quantities is analyzed, and the mechanisms that dominate the growth of the flame kernel are identified. An expression for the speed of turbulent premixed spherical flames is formulated, based on the rate of change of the surface area of the flame.