How Can I Build a Self-Operating Miniature Submarine?

[SilentAssassin2005]

I have to make a miniature submarine, no bigger than the average purse, that floats in a 30 gallon tank, then sinks, comes back to the suface, sinks once more, and then comes back to the surface again. I can not use any chemicals or anything that will change the water colors or any gas. I am also not allowed to touch the submarine after I set it in the water. I can not use any remote controlled subs or anything like that and it has to be homemade. I need lots of help because the only one I can think of I have to use a straw or squeeze the bottle...which I am not allowed to do. Anyhelp would be wonderful. Thank you.

--S1l3nt 4554551n

 

[Andrew Mason]

I have to make a miniature submarine, no bigger than the average purse, that floats in a 30 gallon tank, then sinks, comes back to the suface, sinks once more, and then comes back to the surface again. I can not use any chemicals or anything that will change the water colors or any gas. I am also not allowed to touch the submarine after I set it in the water. I can not use any remote controlled subs or anything like that and it has to be homemade. I need lots of help because the only one I can think of I have to use a straw or squeeze the bottle...which I am not allowed to do.

In order to sink, the sub has to acquire an average density greater than the surrounding water. The way real submarines do this is by taking on just enough water into their ballast tanks to make their average density of the sub equal to the density of water at the level they wish to descend to. To ascend, they force the water out by letting compressed air into the ballast tanks.

In order to make your sub descend, you will have to let water in - a small hole in the bottom of the sub should do the trick. You will then have to force that water out and replace it with air when the sub is at the bottom to make it ascend. A compressed air source in the sub that is regulated by a pressure valve (ie. it is open only when the water pressure is equal to the pressure at the tank bottom) would work. If the hole in the sub is small enough the air will gradually leak out until the water pressure makes the water flow in and the sub will start descending again and the process is repreated.

AM

 

[wais]

Wow, that sounds like quite a challenge! Here are a few ideas that might help you with your project:

1. Use a balloon as a buoyancy control device. Fill a small balloon with air and attach it to the top of your submarine. As the balloon fills with water, it will sink, and as it releases air, it will rise to the surface.

2. Use a syringe to control the water level inside the submarine. By filling the syringe with water and then releasing it, you can control the amount of water inside the submarine and therefore its buoyancy.

3. Use a small motor or propeller to create movement. Attach a small motor or propeller to your submarine and use it to propel the submarine through the water. This will add an extra element of realism to your project.

4. Create a mechanism to release air from the submarine. By using a small valve or release mechanism, you can release air from the inside of the submarine, causing it to sink. Then, when you want it to rise again, you can use the balloon or syringe methods mentioned above to refill the submarine with air.

Remember to be creative and think outside the box. There are many different materials and objects that you can use to create a functioning miniature submarine. Good luck with your project!