When the droplet impacts things like sand it sends shockwaves to the sand. This is the observation that is made at the University of Minnesota. The thing goes like this. When a water droplet impacts the sand. Part of the droplet will fall between the sand bites. To the point where the droplet touches sand forms the channel where air pressure is lower than around it.
The water pressure pushes water below the sand bites. And then that underpressure area will pull the top of the water droplet up. And it pulls sand up. The rising top of the water causes underpressure. That rises sand up.
You can see that thing in the film above this text. When water droplet touches sand it starts to spread. Then the underpressure will start to pull the droplet upward and the water tower jumps up. Until it falls back to the ground again. The thing is that water droplet acts the same way all the time.
When a droplet travels through the air. It forms a channel where pressure is lower than around it. And that underpressure channel pulls the droplet back to the point where it came. It cannot rise droplets up. But it can cause the effect that they will pull back together.
When a droplet touches the water surface. Surface tension causes the water droplet travels at the surface of the water. The droplet spreads until the underpressure area. Which forms above the point where the droplet hits the surface start to pull water back into the air.
Also, the surface tension causes the water surface acts like a trampoline. And then, the water rises in the form of a tower that collapses through the surface.
The water droplet has the impact energy as all other objects it will transfer energy to a layer which it impacts. There is the possibility that the impact energy of water droplets is so high that it makes potholes in metal.
If the speed of the water droplet is high enough the water molecules can tunnel even to steel. Those molecules will transfer their impact energy to metal. And that causes the shockwave through the layer.
The tunneling effect makes it possible. That the water droplet can make holes even in the metal.
https://scitechdaily.com/scientists-solve-mystery-how-soft-liquid-droplets-erode-hard-surfaces/
Comments
Post a Comment