超疏水表面液滴冻结初期冻结行为传递特性

Characteristics of frost spreading during initial stage of condensed droplet freezing on superhydrophobic surface

针对超疏水表面结霜过程中液滴冻结初期"冰桥"导致冻结行为传递的现象,建立液滴与冻结液滴之间的传质模型,揭示超疏水表面液滴冻结初期冻结行为传递的机制。探究冻结行为传递的条件,揭示表面润湿性及表面温度对"冰桥"形成的影响规律。研究结果表明:当液滴与冻结液滴之间的距离小于临界距离时,"冰桥"才可能形成;表面疏水性能越好,液滴分布越稀疏,"冰桥"形成速度越慢,冻结行为越难以传递;表面温度影响液滴表面与冻结液滴表面水蒸气分压力差,水蒸气分压力差越大,"冰桥"形成速度越快。

Inspired by the phenomenon of "ice bridge" which results in frost spreading during droplet freezing initial period on superhydrophobic surface,a model about mass transfer between droplet and freezing droplet was established. Discipline of frost spreading on superhydrophobic surface was revealed.Condition of frost spreading was researched. Effects of wettability and surface temperature on formation of "ice bridge" were researched.The results show that when the distance between droplet and freezing droplet is less than critical distance,"ice bridge" will potentially form.The more hydrophobic the surface is,the sparser the droplet distribution is,the slower the frost spreading is.Surface temperature affects water vapor pressure difference between droplet and freezing droplet.The bigger the water vapor pressure difference is,the faster the "ice bridge" formation is.