The hidden science behind the bottle-smash trick? Cavitation! Check out this instructional video. If you have a home-built vacuum water bottle, you can easily see the violent implosions as they happen.
Cavitation means that cavities or bubbles are forming in the liquid that we're pumping. These cavities form at the low pressure or suction side of the pump, causing several things to happen all at once:
* The cavities or bubbles will collapse when they pass into the higher regions of pressure, causing noise, vibration, and damage to many of the components.
* We experience a loss in capacity.
* The pump can no longer build the same head (pressure)
* The pump's efficiency drops.
The cavities form for five basic reasons and it's common practice to lump all of them into the general classification of cavitation. This is an error because we'll learn that to correct each of these conditions, we must understand why they occur and how to fix them. Here they are in no particular order :
* Air ingestion (Not really cavitation, but has similar symptoms)
* Internal recirculation
* Flow turbulence
* The Vane Passing Syndrome