二元海水液滴对心碰撞过程数值模拟

In order to study the basic laws of droplet collision and the prediction model of collision results in a seawater circulating cooling system, the volume of fluid (VOF) method is used to capture the two-phase interface, and the dynamic mesh adaptation technology is utilized to improve the solution accuracy, and a direct numerical analysis and simulation of the head-on collision process of binary seawater droplets are carried out. Firstly, the collision experiment of n-tetradecane droplets in nitrogen is numerically simulated to verify the reliability of the numerical model. A numerical study on the head-on collision of equal-sized binary seawater droplets under normal temperature and pressure is carried out, the flow field structure and flow mechanism during the droplet collision process are analyzed, the influence laws of different droplet diameters and different seawater concentrations on the collision process are studied, and two types of collision results, namely coalescence and self-reversal separation, as well as their critical Weber numbers are obtained. A nomogram of the seawater droplet collision results under different Ohnesorge numbers is summarized.

为研究海水循环冷却系统中液滴碰撞的基本规律及碰撞结果预测模型,采用流体体积函数(volume of fluid,VOF)方法捕捉两相交界面,利用动态网格自适应技术提高求解精度,对二元海水液滴的对心碰撞过程进行直接数值分析与模拟.首先对氮气中正十四烷液滴的碰撞实验进行数值模拟,验证了数值模型的可靠性.开展了常温常压下等尺寸二元海水液滴对心碰撞数值研究,分析了液滴碰撞过程流场结构及流动机理,研究了不同液滴直径和不同海水浓度对碰撞过程的影响规律,得到了聚合和自反分离两种碰撞结果类型以及二者的临界Weber数.总结出不同Ohnesorge数下海水液滴碰撞结果诺模图.