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Unread 09-06-2008, 17:40
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Andrew R
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Re: Water Balloon Cannon Optimization

Quote:
Originally Posted by Mr. Freeman View Post
I remember someone on this forum doing tests with PVC barrels to see what can contain them if they explode. They found that duct tape does not help in any way. It will not contain shrapnel.
From what I've read the best way to prevent shrapnel from spreading is to put the pipe in a larger pipe. Every other method is flimsy and only offers a certain degree of protection. Using a larger pipe will contain the shrapnel and let the air exit through the ends. If your cannon is too large to fit in a pipe then I'm sure a box of some sort would work. If we stick with pvc once we exit the testing phase we'll end up with some sort of cage like that.

EDIT
----------------
Here are some questions that I'd like to have some input on:
- Whats the best barrel volume/chamber volume ratio and how does the length of the barrel affect inital velocity (ie what is the ideal volume ratio and barrel length)

- If I could design a sabot that would stay in the barrel (maybe by hitting the mouth of the barrel with some sort of stopper slightly overlapping while letting the water balloon continue into flight) would it rob the water balloon of a significant amount of energy? (I know that there would have to be a way to deal with the additional pressure left in the chamber... but setting that aside for a moment)

- Would a heavier or lighter water balloon go further? Is there an ideal weight somewhere?


I'm taking physics next year so showing me how to do these types of calculations myself would be greatly apperciated also, I am definately interested in it.

Last edited by ab500 : 09-06-2008 at 17:52.
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