水平壁面上液滴吹离的临界风速  

Investigation on Critical Airflow Velocity About Departure of Droplet from Horizontal Wall

作　　者：王晓东[1] 彭晓峰[2] 张欣欣[1] 

机构地区：[1]北京科技大学机械工程学院热能工程系,北京100083 [2]清华大学相变与界面传递现象实验室,北京100084

出　　处：《应用基础与工程科学学报》2006年第3期403-410,共8页Journal of Basic Science and Engineering

基　　金：国家自然科学基金(No.50406001)资助

摘　　要：以空气横掠水平壁面上的液滴作为研究对象,确定液滴脱离时的界面形状,给出沿接触线周边接触角的变化关系,在滞后张力模型的基础上,从力平衡出发建立脱落直径的联立方程,讨论液滴脱离直径与来流速度的关系.随来流速度增加,液滴所受表面力和风力均增加,低来流速度下,表面力起主要控制作用,随来流速度增加,风力比表面力增加得快,导致液滴半径越小,被风吹离所需的临界风速越大.液滴脱离的临界风速还与液滴距平板前缘L的距离有关,表现为L越大,液滴被吹离所需的临界风速越大,且液滴半径越大,L影响越显著.Deals with a droplet on the horizontal wall with airflow over the wall. Based on the derivation of the interfacial shape of the droplet under the critical airflow velocity, the contact angles over the contact line were obtained. Using the hysteresis tension model, a mechanical equilibrium equation describing the dynamic behavior of the droplet departure was derived. The calculation results showed that both interfacial forces and wind force increase with increasing the airflow velocity. At the low airflow velocity the interfacial forces dominate over the wind force. With increasing the airflow velocity, the wind force increases more quickly than the interfacial forces, resulting in that the critical airflow velocity is higher for the droplet with smaller diameter. Furthermore, the distance from the drop to the leading edge of the wall also affects the critical airflow velocity. As the distance increases the critical velocity increases and the more great the diameter of the droplet becomes, the more prominent L affects.

关 键 词：液滴 接触角 接触角滞后 滞后张力 脱离直径 

分 类 号：TK124[动力工程及工程热物理—工程热物理]