【摘要】 对高过冷度条件下单个蒸汽气泡的凝结过程进行了可视化研究,并与现有的计算模型进行了对比。实验结果表明:高过冷度条件下,运动速度较高的气泡脱离后,其底部产生的液体射流现象会加剧气泡的变形和凝结过程;而现有的计算关联式均无法较好地预测该条件下的气泡动力学行为,凝结末期的相对误差超过50%。此外,通过Sobol方法对气泡凝结模型进行了敏感性分析,并定量评估了不同实验范围内Reynolds数、Jacob数以及Prandtl数对气泡凝结的影响程度。更多还原

【Abstract】 A visualized investigation was performed to study the condensation process of a single vapor bubble under high subcooling conditions. The obtained experimental data were compared with the existing correlations. Experimental results show that a liquid jet will form at the bottom of a vapor bubble with high velocity after its detachment at high subcooling, which accelerates bubble deformation and condensation process. In addition, the existing correlations are not able to predict the condensation dynamics of vapor bubble at high subcooling very well, and the relative errors exceed 50% at the end of condensation. Further, the sensitivity analysis was performed with Sobol model to analyze the existing correlations, and the impact of Reynolds number, Jacob number and Prandtl number on bubble condensation process under different conditions was evaluated quantitatively.更多还原