In trying to understand some fluid-dynamic principles, I am trying to discern between a couple water droplet interactions. This droplet video demonstrates the scenarios properly, but unfortunately doesn’t afford a ton of explanation related to the supporting math.
Somewhere around 00:15 two droplets combine in the bottom corner of the screen.
Whereas the video seems a bit more interested in droplets chasing each other.
Forces related to surface tension are definitely at play - and perhaps density as well. But I'm trying to understand what exactly would determine whether two droplets combine or maintain some level of independence. For ex, if we were to track two colliding droplets that were to combine, what threshold in the formula would need to be crossed to convert from colliding to unionized droplets.