Direct Numerical Simulation of Inert Droplet Effects on Scalar Dissipation Rate in Turbulent Reacting and Non-Reacting Shear Layers
Direct Numerical Simulation of Inert Droplet Effects on Scalar Dissipation Rate in Turbulent Reacting and Non-Reacting Shear Layers
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DOI：
10.1007/s10494-009-9238-7
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发表时间：
2010-04
期刊：
影响因子：
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通讯作者：
J. Xia;K. Luo
中科院分区：
文献类型：
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作者：
J. Xia;K. Luo
采用三维直接数值模拟方法，研究了在基于涡量厚度的雷诺数为8000，示踪液滴数为107的条件下，惰性蒸发液滴对瞬态发展的湍流反应和非反应混合层中标量耗散率χ的影响.详细的瞬态场分析和整体平均统计揭示了燃烧、液滴动力学和蒸发之间的复杂相互作用，所有这些都对χ有相当大的影响。惰性蒸发液滴的存在促进了非反应混合层和反应混合层中的χ。在后者中，燃烧降低χ，因此当通过蒸发液滴抑制燃烧时，χ增强。对χ的输运方程进行了分析，详细研究了各种因素对χ的影响。方程中的项明确包含蒸发率及其空间导数，分别充当χ的汇和源。总的来说，蒸发率项的净效应是促进χ。然而，生产和耗散项分别是主要的源项和汇项。
Three-dimensional direct numerical simulation has been performed to investigate the effects of inert evaporating droplets on scalar dissipation rateχin temporally-developing turbulent reacting and non-reacting mixing layers with the Reynolds number based on the vorticity thickness up to 8000 and the number of traced Lagrangian droplets up to 107. The detailed instantaneous field analysis and ensemble-averaged statistics reveal complex interactions among combustion, droplet dynamics and evaporation, all of which have a considerable influence onχ. The presence of inert evaporating droplets promotesχin both non-reacting and reacting mixing layers. In the latter, combustion reducesχ, so when combustion is suppressed by evaporating droplets,χis enhanced. The transport equation ofχhas been analyzed to investigate the various effects onχin detail. The terms in the equation contain explicitly the evaporation rate and its spatial derivative, acting as a sink and a source forχ, respectively. On the whole, the net effect of the evaporation-rate terms is to promoteχ. However, the production and dissipation terms are the dominant source and sink terms, respectively.