Modeling drop breakage using the full energy spectrum and a specific realization of turbulence anisotropy
Modeling drop breakage using the full energy spectrum and a specific realization of turbulence anisotropy
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DOI：
10.1002/aic.17201
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发表时间：
2021-02
期刊：
影响因子：
3.7
通讯作者：
Ioannis Bagkeris;V. Michael;R. Prosser;A. Kowalski
中科院分区：
文献类型：
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作者：
Ioannis Bagkeris;V. Michael;R. Prosser;A. Kowalski
当在工业相关几何形状中模拟液滴破碎时，均匀各向同性湍流的假设是有问题的。我们描述了各向异性破碎模型的发展，其中各向异性是通过包含扰动湍流谱引入的。扰动谱的选择本身就是我们以前对高压均质器的大涡模拟的动机。该模型将能量从小尺度重新分配到大尺度，并假设雷诺应力的各向异性部分仅限于能量范围。在Coulaloglou和Tavlarides的标准框架中，由扰动谱产生的二阶结构函数用于计算断裂频率。虽然基础模型表现出非单调的行为（通过预测某个液滴尺寸的最大值），各向异性的影响被证明是增加破碎频率的长度尺度大于这个峰值，从而减少非单调性。这种效应在湍流雷诺数较小时更为明显。
The assumption of homogeneous isotropic turbulence when modeling drop breakage in industrially relevant geometries is questionable. We describe the development of an anisotropic breakage model, where the anisotropy is introduced via the inclusion of a perturbed turbulence spectrum. The selection of the perturbed spectrum is itself motivated by our previous large-eddy simulations of high-pressure homogenizers. The model redistributes energy from small to large scales, and assumes that the anisotropic part of the Reynolds stresses is confined to the energy-containing range. The second-order structure function arising from the perturbed spectrum is used in the standard framework of Coulaloglou and Tavlarides to calculate breakage frequency. While the base model exhibits non-monotonic behavior (by predicting a maximum value for a certain drop size), the effect of anisotropy is shown to increase breakage frequency in length scales larger than this peak, thereby reducing non-monotonicity. This effect is more pronounced for small turbulence Reynolds numbers.