竖直加热通道内气泡脱离直径预测模型

Bubble departure diameter predicted model in vertical boiling system

气泡脱离是气泡蒸发中的一个自然现象,它通过扰动边界层的速度和温度来影响沸腾传热,对泡核沸腾传热影响重大。现有的气泡脱离直径模型往往非常复杂,需要开发专用程序进行计算,难以在大型CFD软件中直接嵌入使用,为解决这个问题,本文开发一种计算过程较为简便,易于CFD软件嵌入的竖直加热通道气泡脱离直径模型。本文采用受力平衡方法建立了竖直加热通道内气泡脱离直径预测模型,并采用盛金公式进行数学处理,获得气泡脱离直径的解析解,使模型得到简化,经与公开文献中的实验数据进行对比,结果表明,理论模型与实验数据之间的误差小于22.29%。

Bubble departure diameter has a significant effect on nucleate boiling heat transfer characteristics,so it is necessary to study it in depth.The existing models are usually developed empirically and the bubble departure diameter model established based on dimensionless numbers is not clear in the physical significance.In this paper,a theoretical prediction model of bubble departure diameter is established based on the force analysis.Chen’s experimental data is used to validate the model,the averaged relative deviation between the predict results of the model and the experimental data is less than 22.29%.