液滴撞击壁面铺展及换热过程数值模拟

基于喷雾冷却时液滴撞击壁面现象,本文采用CLSVOF(coupled level set and volume of fluid)方法对不同工况下单液滴撞壁过程进行数值模拟,获得了单液滴撞击热壁面动态特性;分析了初始速度、液滴直径等初始参数对液滴撞壁后的动态铺展规律以及壁面换热特性的影响规律,获得了上述参数变化时液滴铺展系数和热流密度的变化趋势;探讨了场协同效应、液滴内部气泡以及三线接触点对壁面换热的影响。碰壁现象的研究对于大型制冷机组室外机散热、高热流电子器件散热等领域优化与控制喷雾有重要意义。

Numerical simulation of spreading of droplet on wall and heat transfer process

Based on the phenomenon when droplets impinging on the wall during industrial spray cooling, CLSVOF(Coupled Level Set and Volume of Fluid) method was used to simulate the impinging process of single droplets under different conditions, and the dynamic characteristics of single droplets impinging on the hot wall were obtained. The influences of initial parameters such as initial velocity droplet and diameter on the dynamic spread law and wall heat transfer characteristics of droplet after impact were analyzed. The changing trends of droplet spreading coefficient and heat flux density were obtained when the above parameters changed. The effects of field synergy, bubbles inside the droplets and three-line contact points on the wall heat transfer were discussed. The study of the wall collision phenomenon is of great significance to the optimization and control of spraying in the industrial fields of heat dissipation and alloy quenching of outdoor units of large refrigeration units.