中空液滴撞击液膜的数值研究  

Numerical Study on the Impact of Hollow Droplet on Liquid Film

作　　者：闫哲 李艳[1] YAN Zhe;LI Yan(College of Engineering,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学工程学院,山东青岛266100

出　　处：《高校化学工程学报》2018年第3期529-536,共8页Journal of Chemical Engineering of Chinese Universities

基　　金：山东省重点研发计划项目(2017GHY15113);国家自然科学基金(51376164)

摘　　要：采用耦合水平集-体积分数法(CLSVOF)建立了中空液滴撞击液膜的数值模型,进行了模型的准确性验证,对中空液滴撞击液膜的动态特性及传热特性进行了研究。结果表明,中空液滴撞击液膜的动态过程包含液壳破碎、液壳液膜融合、液滴铺展等过程。中空液滴撞击液膜时会出现空气卷吸现象及颈部射流现象,颈部射流现象产生的原因是由于液滴颈部位置存在较大的局部压差。随着时间的推移,近壁面处流体的温度逐步上升,壁面的热流密度逐步降低,撞击过程对于传热特性所产生的影响趋于明显。分析了液壳厚度、液膜厚度及撞击速度对传热特性所产生的影响,壁面的平均热流密度随着液壳厚度及撞击速度的增大而增大,随着液膜厚度的增大而减小。A numerical model of hollow droplet impact on liquid film was developed based on（coupled level set and volume of fluid） CLSVOF and validated. The dynamic and heat transfer characteristics of the impact were studied. The results show that the dynamic impact process includes liquid shell broken, coalescence between liquid shell and liquid film and droplet spreading. Phenomena of air bubble entrapment and jetting flow are observed. The reason of jetting flow is due to the existence of larger local pressure difference in the neck region. Liquid temperature near wall increases and heat flux density decreases with the increase of time, and effect of droplet impact becomes more obvious. Effects of liquid shell thickness, liquid film thickness and impact velocity on heat transfer characteristics were analyzed. The average heat flux of wall increases with the increase of liquid shell thickness and impact velocity, and it decreases with the increase of liquid film thickness.

关 键 词：中空液滴 液膜 撞击 传热 

分 类 号：O359.1[理学—流体力学] TK01[理学—力学]