当量滴径对于液滴驻留液面时间尺度影响的研究

液滴撞击液面的现象在自然界和工业应用中广泛存在,像雨滴下落,喷雾冷却,喷墨打印,微流控芯片等。液滴撞击液面后,在界面处产生Marangoni效应,液滴与液面间形成一层被截留的空气薄膜,进而阻止了液滴与液面的瞬间聚结,导致液滴在液面产生驻留。本文采用高速摄像机以6400fps的帧频对不同尺寸液滴驻留液面的时间尺度进行实验探究。结果表明:液滴在液面驻留的时间尺度τd与当量滴径D d-1/2呈线性相关的关系。

The phenomenon of droplet hit on liquid surface exists widely in nature and industrial applications,such as raindrop falling,spray cooling,inkjet printing,microfluidic chip,etc.After the droplet hits the liquid surface,the Marangoni effect occurs at the interface,forming a layer of trapped air film between the droplet and the liquid surface,which prevents the instantaneous coalescence of the droplet and the liquid surface,causing the droplet to stay at the liquid surface.A high-speed camera is used to explore the time scale of liquid droplet of different sizes at 6400 fps frame.The results show that the equivalent diameter Dd-1/2 of the droplet is linearly correlated with the residence timeτd at the liquid surface.