Influence of multiphase turbulence modelling on interfacial momentum transfer in two-fluid Eulerian-Eulerian CFD models of bubbly flows
Influence of multiphase turbulence modelling on interfacial momentum transfer in two-fluid Eulerian-Eulerian CFD models of bubbly flows
复制标题
多相湍流建模对气泡流双流体欧拉-欧拉 CFD 模型中界面动量传递的影响
DOI：
10.1016/j.ces.2018.10.043
复制
发表时间：
2019
影响因子：
4.7
通讯作者：
Colombo M
中科院分区：
文献类型：
--
作者：
Colombo M
欧拉-欧拉双流体计算流体动力学(CFD)模型越来越多地被用于预测工业规模的气泡流动。在这些方法中，界面传递是用闭合模型和相关性来建模的。通常认为，空泡率的横向分布主要是由升力和壁面润滑力之间的平衡造成的。然而，尽管现有的许多模型至少在管流中实现了合理的预测精度，但尚未就广泛适用和准确的建模方法达成一致意见。此外，湍流模型对横向含气率分布的影响通常还没有详细研究过。在这项工作中，椭圆混合雷诺应力模型(EB-ε)，能够解决近壁区的湍流场，并改进以考虑气泡诱导的湍流的贡献，与最佳实用的EK-ε和高雷诺二阶矩湍流闭合进行了评估。在EB-RSM中，最初故意忽略升力和壁面润滑力。对管内流动和方形管道流动的比较表明，EB-RSM模型再现了含气率的横向分布，包括近壁区含气率的峰值，达到了与上述另外两个模型相当的精度。在棒束中，即使所考虑的模型没有一个具有足够的精度，EB-RSM也会检测到其他两种方法无法预测的流动特征。总体而言，结果表明湍流结构和诱导截面压力场对横向含气率分布的影响比通常认为的要显著得多。如果要实现泡状流的物理上更一致的建模，就需要考虑这些影响。在本文的最后部分，将升力添加到EB-RSM中，以提供一个双流体公式，该公式可用作旨在提高双流体CFD模型的精度和普遍适用性的进一步开发的基础。
Eulerian-Eulerian two-fluid computational fluid dynamic (CFD) models are increasingly used to predict bubbly flows at an industrial scale. In these approaches, interface transfer is modelled with closure models and correlations. Normally, the lateral void fraction distribution is considered to mainly result from a balance between the lift and wall lubrication forces. However, and despite the numerous models available that achieve, at least in pipe flows, a reasonable predictive accuracy, agreement on a broadly applicable and accurate modelling approach has not yet been reached. Additionally, the impact of turbulence modelling on the lateral void fraction distribution has not, in general, been examined in detail. In this work, an elliptic blending Reynolds stress model (EB-RSM), capable of resolving the turbulence field in the near-wall region and improved to account for the contribution of bubble-induced turbulence, is evaluated against best-practicek-εand high-Reynolds second-moment turbulence closures. Lift and wall lubrication forces are initially deliberately neglected in the EB-RSM. Comparisons for flows in pipes and a square duct show that the EB-RSM reproduces the lateral void fraction distribution, including the peak in the void fraction in the near-wall region, and reaches an accuracy comparable to the other two models noted above. In rod bundles, even if none of the models considered performs with sufficient accuracy, the EB-RSM detects features of the flow that are not predicted by the other two approaches. Overall, the results demonstrate a much more prominent role of the turbulence structure and the induced cross-sectional pressure field on the lateral void fraction distribution than is normally considered. These effects need to be accounted for if more physically-consistent modelling of bubbly flows is to be achieved. The lift force is added to the EB-RSM in the final part of the paper, to provide a two-fluid formulation that can be used as the basis for additional developments aimed at improving the accuracy and general applicability of two-fluid CFD models.
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影响因子：
4.7
作者：
M. Colombo;M. Fairweather
通讯作者：
M. Colombo;M. Fairweather
影响因子：
4.7
作者：
T. Hibiki;M. Ishii
通讯作者：
T. Hibiki;M. Ishii
DOI：
10.1016/j.ijmultiphaseflow.2015.09.003
发表时间：
2015-12
影响因子：
3.8
作者：
M. Colombo;M. Fairweather
通讯作者：
M. Colombo;M. Fairweather
DOI：
10.1016/j.ijheatfluidflow.2014.09.002
发表时间：
2015
影响因子：
2.6
作者：
R. Manceau
通讯作者：
R. Manceau
评估 STAR-CCM 和 OpenFOAM 中低体积分数状态的一组简化动量闭合关系
DOI：
--
发表时间：
2017
期刊：
影响因子：
--
作者：
R. Sugrue;B. Magolan;N. Lubchenko;E. Baglietto
通讯作者：
E. Baglietto