单液滴撞击球形表面的涂覆效果

Coating and the Impact of Single Droplet on the Spherical Surface

液滴与球形表面的碰撞为喷雾包衣等工程应用的基础.以单液滴与球形光滑表面为研究对象,采用高速相机,分析了在液滴不同撞击速度(0.88～4.43 m/s)和不同直径的球面(5～15mm)实验条件下涂覆率的变化.研究了液滴与球面发生碰撞时发生的铺展震荡、涂覆球面、破碎飞溅现象.最后,建立了K值、球面直径与碰撞现象之间的关系图,为理论分析和数值模拟提供依据.

Droplet-spherical surface collision is a fundamental issue in the application of spray coating. Under the experi- mental conditions of different impact velocity（0.88-4.43 m/s）and different outer diameters of the spherical surface（5- 15 mm）, the impact of a single droplet on a spherical surface at room temperature was investigated by analyzing the changes of coating with the help of a high-speed camera. When contacting the spherical surface, the droplet spreads, retracts, relaxes or splashes on the surface. Consequently, the relationship between the K value, sphere diameter and impacting phenomena was established for theoretic analysis and numerical simulation.