过热度对单汽泡生长及壁面传热的影响规律研究

核态沸腾以其高效的传热能力被广泛应用于各种工业领域。文章基于流体体积(volume of fluid, VOF)法建立考虑微液层蒸发的单汽泡生长模型,对核态沸腾单汽泡的生长与脱离过程进行模拟,研究壁面过热度对沸腾汽泡生长与传热过程的影响。结果表明:该模拟方法可以准确预测汽泡尺寸及壁面温度分布;汽泡脱离直径和汽泡影响面积均会随着壁面过热度的增大而增大;汽泡影响因子K会随着加热面过热度的增加而减小。文章研究结果有助于提高壁面热流分区模型的预测精度,并为揭示沸腾的强化传热机理提供了依据。

Nucleate boiling is widely used in various industrial fields due to its highly efficient heat transfer ability. In this paper, a single bubble growth model considering microlayer evaporation is established based on the volume of fluid (VOF) method. The growth and separation process of bubble in nuclear boiling state is simulated. The influence of wall superheat on the growth and heat transfer of bubble is studied. The results show that the simulation method can accurately predict the bubble size and wall temperature distribution. The bubble departure diameter and bubble influence area increase with the increase of wall superheat. The bubble influence factor K decreases with the increase of the superheat of the heating surface. The results can improve the predictive accuracy of the wall heat flux partitioning models and contribute to uncovering the mechanism of boiling heat transfer enhancement.