Towards understanding turbulent scalar mixing
Towards understanding turbulent scalar mixing
复制标题
理解湍流标量混合
DOI：
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发表时间：
1992
期刊：
影响因子：
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通讯作者：
S. Girimaji
中科院分区：
文献类型：
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作者：
S. Girimaji
为了理解湍流标量混合，我们首先单独研究分子混合的影响，然后考虑速度场的影响。这种方法的主要动机源于从湍流速度场中产生的热传导方程演化而来的标量场获得的标量概率密度函数 (PDF) 的高度相似性。然而，两种情况下标量耗散的演变是不同的。我们尝试使用拉格朗日框架分析来解释这些由速度场引起的差异。在确定这种方法的实用性后，我们使用热传导模拟 (HCS) 代替更昂贵的直接数值模拟 (DNS)，来研究湍流混合的许多不太了解的方面。只要有可能，就会对 HCS 数据和可用模型进行比较。已确定 beta PDF 表征了在所有类型的非预混合初始条件的混合过程中标量 PDF 的演变。
In an effort towards understanding turbulent scalar mixing, we study the effect of molecular mixing, first in isolation and then by accounting for the effects of the velocity field. The chief motivation for this approach stems from the strong resemblance of the scalar probability density function (PDF) obtained from the scalar field evolving from the heat conduction equation that arises in a turbulent velocity field. However, the evolution of the scalar dissipation is different for the two cases. We attempt to account for these differences, which are due to the velocity field, using a Lagrangian frame analysis. After establishing the usefulness of this approach, we use the heat-conduction simulations (HCS), in lieu of the more expensive direct numerical simulations (DNS), to study many of the less understood aspects of turbulent mixing. Comparison between the HCS data and available models are made whenever possible. It is established that the beta PDF characterizes the evolution of the scalar PDF during mixing from all types of non-premixed initial conditions.