A Priori Direct Numerical Simulation Modeling of Scalar Dissipation Rate Transport in Head-On Quenching of Turbulent Premixed Flames
A Priori Direct Numerical Simulation Modeling of Scalar Dissipation Rate Transport in Head-On Quenching of Turbulent Premixed Flames
复制标题
湍流预混火焰正面淬火中标量耗散率传递的先验直接数值模拟
DOI：
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
N. Chakraborty
中科院分区：
文献类型：
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作者：
J. Lai;N. Chakraborty
在基于三维简单化学直接数值模拟（DNS）数据的Reynolds平均Navier-Stokes模拟中，分析了惰性等温壁对湍流预混火焰正面淬火的标量耗散率（SDR）输输的统计行为和建模。研究发现，密度变化、标度-湍流相互作用、反应速率梯度、分子扩散梯度和分子耗散项，即和，分别是SDR离壁面输运的主要因素，与其他项相比，湍流输运和分子扩散项可以忽略不计。研究发现，在淬灭开始前，SDR输运的主要序元处于远离壁面的粗略平衡状态，但在火焰淬灭过程中，这种平衡不被维持。根据从DNS数据中提取的相应数量，评估了现有模型对SDR输运方程的非封闭项的预测。没有发现现有的模型来预测SDR输运方程的非封闭项的近壁行为。这些模型在离壁处表现出最令人满意的性能，为了考虑近壁行为，已经对模型进行了修改，使修改后的模型逐渐接近于离壁处的现有模型表达式。
ABSTRACT The statistical behavior and modeling of scalar dissipation rate (SDR) transport for head-on quenching of turbulent premixed flames by an inert isothermal wall have been analyzed in the context of Reynolds averaged Navier–Stokes simulations based on three-dimensional simple chemistry direct numerical simulation (DNS) data. It has been found that the density variation, scalar-turbulence interaction, reaction rate gradient, molecular diffusivity gradient, and molecular dissipation terms, i.e., , and , respectively, act as leading order contributors to the SDR transport away from the wall and the turbulent transport and molecular diffusion terms remain negligible in comparison to the other terms. The leading order contributors to the SDR transport have been found to be in a rough equilibrium away from the wall before the quenching is initiated but this equilibrium is not maintained during flame quenching. The predictions of the existing models for the unclosed terms of the SDR transport equation have been assessed with respect to the corresponding quantities extracted from DNS data. No existing models have been found to predict the near-wall behavior of the unclosed terms of the SDR transport equation. The models, which exhibit the most satisfactory performance away from the wall, have been modified to account for near-wall behavior in such a manner that the modified models asymptotically approach the existing model expressions away from the wall.
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影响因子：
4.4
作者：
Chakraborty, Nilanjan;Cant, R. S.
通讯作者：
Cant, R. S.
影响因子：
4.4
作者：
D. Butz;Yuan Gao;A. Kempf;N. Chakraborty
通讯作者：
D. Butz;Yuan Gao;A. Kempf;N. Chakraborty
影响因子：
4.6
作者：
N. Chakraborty;N. Swaminathan
通讯作者：
N. Chakraborty;N. Swaminathan
DOI：
10.1007/s10494-010-9250-y
发表时间：
2010-02
期刊：
Flow, Turbulence and Combustion
影响因子：
--
作者：
N. Chakraborty;J. Rogerson;N. Swaminathan
通讯作者：
N. Chakraborty;J. Rogerson;N. Swaminathan
影响因子：
4.6
作者：
N. Chakraborty;R. Cant
通讯作者：
N. Chakraborty;R. Cant