Abstract The T-junction exists widely in industrial engineering, especially in nuclear power plants, which plays an important part in nuclear power reactor thermal-hydraulics. However, the existing prediction models of the liquid entrainment are mainly based on the small branches or small breaks while there are a few researches for large branches (d/D > 0.2). Referring to the classical models about the onset of liquid entrainment of the T-junction, most of previous models regard liquid as ideal working fluid and ignore surface tension. This paper aims to study the effect of surface tension on the liquid entrainment, and develops an improved model based on the reasonable assumption. The establishment of new model employs the methods of force analysis, dimensional analysis. Besides, the dimensionless Weber number is adopted innovatively into the model to show the effect of surface tension. What is more, in order to validate the new model, three kinds of working fluids with different surface tensions are creatively adopted in the experiments: water, silicone oil and ethyl alcohol. The final results show that surface tension has a nonnegligible effect on the onset of liquid entrainment in large branch T-junction. The new model is well matched with the experimental data.

中文翻译：

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考虑表面张力的大分支T型接头液体夹带开始模型

摘要 T型接头广泛存在于工业工程中，特别是在核电站中，在核动力反应堆热工水力方面起着重要的作用。然而，现有的液体夹带预测模型主要基于小分支或小断裂，而对大分支（d / D > 0.2）的研究很少。参考关于 T 型接头液体夹带开始的经典模型，以前的大多数模型都将液体视为理想的工作流体，而忽略了表面张力。本文旨在研究表面张力对液体夹带的影响，并基于合理假设开发改进模型。新模型的建立采用力分析、量纲分析的方法。除了，模型中创新地采用了无量纲韦伯数来展示表面张力的影响。更重要的是，为了验证新模型，实验中创造性地采用了三种不同表面张力的工作流体：水、硅油和乙醇。最终结果表明，表面张力对大分支 T 型接头中液体夹带的开始具有不可忽略的影响。新模型与实验数据吻合良好。最终结果表明，表面张力对大分支 T 型接头中液体夹带的开始具有不可忽略的影响。新模型与实验数据吻合良好。最终结果表明，表面张力对大分支 T 型接头中液体夹带的开始具有不可忽略的影响。新模型与实验数据吻合良好。