流动沸腾条件下窄通道内的汽泡生长和冷凝

Bubble Growth and Condensation in Narrow Channel of Subcooled Flow Boiling

  • 摘要: 针对过冷沸腾条件下窄通道内的汽泡生长和冷凝进行实验研究。实验中观察到了两类汽泡的生长和冷凝,分别称为第1类汽泡和第2类汽泡。其中第1类汽泡生长速度较快,且在滑移离开核化点之后迅速冷凝消失。而第2类汽泡的生长速度较慢,且滑移很长一段距离后也不会冷凝消失,具有更长的存活时间。两类汽泡的生长可采用不同的关系式进行预测,且生长冷凝特性均表现出很强的随机性,体现出汽泡周围环境的微小变化对汽泡行为的影响。

     

    Abstract: Bubble growth and condensation in narrow channel under subcooled flow condition was experimentally studied in this paper. Two types of bubbles with totally different growth and condensation characteristics were observed, denoted as the first type bubble and the second type bubble. The growth rate of the first bubble is rather faster and the bubble disappears after condensation once the bubble departure the nucleation site. While a smaller growth rate could be observed for the second type bubble and the lifetime is much longer. The condensation effect could not cause the collapse of the second type bubble even for the longer sliding distance. The growth of the two types bubbles could be predicated by different correlations. Strongly random characteristics of the growth and condensation of bubble were observed in the present experiment, which is caused by the small variation of the local conditions of the subcooled boiling.

     

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