If you have ever built yourself a potato gun, you know just how fun and possibly dangerous the cannons can be. They are pretty simple to make and they just require a little hairspray to send those taters flying! While shooting these guns are fun, what is really going on inside of the combustion chamber, and what is the perfect place to ignite the fuel? Smarter Every Day on Youtube has taken on that question and built a clear potato gun. The result was filmed in high-speed, and it is nothing less than spectacular.
As you may have expected, explosions are amazing to watch in ultra high-speed. In order to build a potato gun, you will need some PVC, some hairspray, and a BBQ lighter. The BBQ lighter is used to spark the aerosolized fuel and set everything in motion. After you cram a potato in the end of the gun, everything becomes sealed allowing for the combustion process to do work on the taterjectile (yes, I did just combine the word tater and projectile).
One long-standing misconception Destin from Smarter Every Day had about the gun was where to place the ignition source. Traditionally it is placed in the end on the cap, but he always thought placing it in the center would allow for more even combustion. After recording this in high-speed, he found that he was very wrong. By placing the ignition source in the center of the combustion chamber, the explosion runs out of oxygen near the cap before all of the fuel can be burnt off. This results in undulating explosions following the expulsion of the taterjectile.
[Image Source: SmarterEveryDay]
If you enjoy learning about combustion, or just having a fun time shooting potatoes, building yourself one of these devices is a blast.