Abstract According to the force balance analysis on a bubble, the bubble departure diameter in horizontal subcooled flow boiling is mainly influenced by quasi-steady drag force, surface tension force and bubble growth force while an additional force, buoyancy force, plays an important role in vertical flow boiling. In this paper, the effects of these forces can be concluded by a series of dimensionless parameters including density ratio of vapor and liquid, Prandtl number, Jacob number and bubble Reynolds number. Based on the different forces, two different characteristic lengths are adopted to non-dimensionlize bubble departure diameters in horizontal flow boiling and vertical flow boiling, respectively. Finally, the semi-empirical correlations for bubble departure diameters in both horizontal and vertical subcooled flow boiling are proposed in this paper based on the force balance analysis and available experimental data from literature. The predicted results using the present correlations agree fairly well with the experimentally measured values with a mean relative error of 19.72%.

中文翻译：

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水平和垂直过冷流沸腾中气泡离开直径的研究

摘要 根据气泡受力平衡分析，水平过冷流沸腾中气泡离开直径主要受准定常拖曳力、表面张力和气泡生长力的影响，附加力浮力在其中起重要作用。垂直流动沸腾。在本文中，这些力的影响可以通过一系列无量纲参数得出，包括汽液密度比、普朗特数、雅各布数和气泡雷诺数。根据作用力的不同，分别采用两种不同的特征长度对水平流动沸腾和垂直流动沸腾中的气泡离开直径进行无量纲化。最后，本文基于力平衡分析和文献中可用的实验数据，提出了水平和垂直过冷流沸腾中气泡离开直径的半经验相关性。使用当前相关性的预测结果与实验测量值非常吻合，平均相对误差为 19.72%。