Gas-liquid flow of sub-millimeter bubbles at low void fractions: Void fraction prediction using drift-flux model
Gas-liquid flow of sub-millimeter bubbles at low void fractions: Void fraction prediction using drift-flux model
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DOI：
10.1016/j.expthermflusci.2018.05.018
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发表时间：
2018-11
影响因子：
3.2
通讯作者：
S. Evgenidis;T. Karapantsios
中科院分区：
文献类型：
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作者：
S. Evgenidis;T. Karapantsios
漂移通量模型是预测两相流含气率的一种简单可靠的方法。这项工作检查了它在低空隙率（<10−1）下小气泡（<1 mm）的气液流动中的性能，这类似于减压病期间人类血流中的气泡流动，也可以在其他两相应用中找到，例如宏观通道中的流动沸腾。漂移通量模型的预测进行了比较，在并流向上泡状流的实验数据测量不同的气体/液体流动特性。将水和血液模拟物用作试验液体，同时使用规定的表面活性剂（SDS）浓度控制气泡大小。均质流模型是漂移流模型的一个子模型，当气泡平均尺寸小于200 μm时，可以很好地预测水和血液模拟物中的含气率。对于水中的大气泡（平均尺寸达800 μm）和血液模拟物中的大气泡（平均尺寸达350 μm），检查了来自文献的13个漂移通量模型的性能。其中10个专门涉及泡状流，而三个模型适用于广泛的流动条件。据我们所知，这是第一次，漂移通量模型进行了测试，在组合的低空隙率（之间的1010 - 3和1010 - 1）和亚毫米气泡尺寸，因此漂移通量参数（分布参数，C 0和漂移速度，Ugm）的确定进行了详细说明。在此基础上，提出了一种与气泡尺寸相关的关联式。
Drift-flux model is a simple and reliable tool for void fraction prediction in two-phase flows. This work examines its performance in gas-liquid flow of small bubbles (<1 mm) at low void fractions (<10−1) that resembles bubbly flow in human bloodstream during Decompression Sickness and can be also found in other two-phase applications such as flow boiling in macro-channels. Drift-flux model predictions are compared with experimental data measured in co-current upward bubbly flow for varying gas/liquid flow properties. Water and blood simulant are used as test liquids, while bubble size is controlled using prescribed surfactant (SDS) concentrations. Homogeneous flow model, which is a sub-case of drift-flux model, predicts adequately void fraction in water and blood simulant when the mean bubble size is lower than 200 μm. For larger bubbles in water (mean size up to 800 μm) and in blood simulant (mean size up to 350 μm), the performance of thirteen drift-flux models from literature is examined. Ten of them concern specifically bubbly flow, whereas three models are applicable to a wide range of flow conditions. To our knowledge, this is the first time that drift-flux models are tested at combined low void fractions (between ∼10−3and ∼10−1) and sub-millimeter bubble sizes, so the determination of drift-flux parameters (distribution parameter,C0and drift velocity,Ugm) is elaborated. On this account, a bubble size dependent correlation is proposed forUgmdetermination.