Need to increase altitude

[runnin_rocket_maker]

Hi I am in a competition with my physics class to create the best water rocket. In this case "best" means who's rocket can fly the highest, i am looking for tips or tricks of the trade that any of you more advanced, or beginner engineers can give me. Thanks

[Jelo]

check out my page on stability, which should keep your rocket flying upwards and in the most efficient way:

http://www.wra2.org/forum/viewtopic.php?f=3&t=764
please post about the current fins you use

[zetez]

If you don't have any accurate rules, you may add a foam to the water.

[U.S. Water Rockets1]

Hi I am in a competition with my physics class to create the best water rocket. In this case "best" means who's rocket can fly the highest, i am looking for tips or tricks of the trade that any of you more advanced, or beginner engineers can give me. Thanks

If you are only allowed to use bottles, you should design your rocket to use a series of skinny bottles spliced together to make a narrow rocket with a few liters of volume. The lighter you can make it the better as well. The lightest rocket with the least drag will win.

Good luck!

[runnin_rocket_maker]

The fins i am using currently are cardboard. just for a prototype i am changing this to either a hard plastic or liuena board. (the size is approximately 6x11 in parallelogram)

The rules are as follows, the engine must be one 2 liter bottle, there will be 24 oz. of water at 70 psi.

Currently my rocket is about 2.5 two liters tall i'm not sure of a good way to decrease down to a smaller rocket for the nosecone without increasing drag.

Another question is would decreasing the size of the engine increase the thrust?
I.e. using a Bunsen burner to mold the engine to a smaller size?

Thanks again for everyone's help P.S. my first test launch was 263 ft.

[rockets-in-brighton]

The fins i am using currently are cardboard. just for a prototype i am changing this to either a hard plastic or liuena board. (the size is approximately 6x11 in parallelogram)

The rules are as follows, the engine must be one 2 liter bottle, there will be 24 oz. of water at 70 psi.

Currently my rocket is about 2.5 two liters tall i'm not sure of a good way to decrease down to a smaller rocket for the nosecone without increasing drag.

Another question is would decreasing the size of the engine increase the thrust?
I.e. using a Bunsen burner to mold the engine to a smaller size?

Thanks again for everyone's help P.S. my first test launch was 263 ft.

Fins need to be stiff (to stop them flapping) and light. Any material that achieves this is fine. If it only has to launch once go for the lightest material and don't worry if it gets smooshed when it lands (but make replacements for testing of course)

Is your nosecone a supplied one, of a different size to the pressure bottle? If not, don't add extra bottles at the top - you just need to have a reasonably aerodynamic cover on the top but you don't need any extra length if you are adding enough fin area to get the centre of pressure low. If your test flight achieved 260 feet then your rocket is flying straight already.

If your launch pressure is fixed, the only useful modification you can make to the pressure vessel is to reduce the size of the nozzle - but you can only do that if the launcher being used will allow it. More information there, please.

Best of luck!

[runnin_rocket_maker]

My fins are currently made of a very light but sturdy hard plastic covered in aluminum tape, i think aluminum will have very little drag.

The nose cone is not supplied and is currently the top of a bottle with the neck cut out, in the hole i have placed a golf ball and covered with tape, this gave me the most "bullet shaped" cone

I cannot change the size of the nozzle because the fitting that pressurizes the engine fits into the neck, however i did think about this idea. My conclusion was that only on a very light rocket would this work because the initial pressure needed to lift the rocket would need to be greater.

I would appreciate anyone's ideas or thoughts on these topics or any other topic as i like to "talk rockets"

I am trying to convince another teacher to let me launch the rocket at a higher pressure than 70 PSI, my current teacher said anything above that is unsafe

[Jelo]

first, i wouldn't go for aluminium as it is heavy (altough it seems very light) i personaly use plastic board with a bamboo skewer to re-enforce it, but if you have a preference for aluminium thats fine

secondly, why a golf ball? ping pong balls are aproximatly the same size but weigh 10 times less (if not more)

and tell your teacher coke bottles are made to withstand 90 psi so are guaranteed not to blow up before that

[eljose707]

omg i have the same competition!!! of course not with the same specs lol