Best fins for water bottle rocket design?

[Habesha Capt_Joshua]

Hi everyone! So for my Physics class we will be doing a water bottle rocket competition where the rocket that lasts in the air the longest wins. What type of shape should my fins be and how should I set them up so that my rocket can glide and stay in the air the longest, once it has reached its max altitude? Also any things I should be considering when building and designing?

[MAD]

Try little delta fins ever so slighty angled to spin your bottle for stability.
Smaller fins less drag.

Wrap bottle in tape so it can take extra pressure without rupturing.

Experiment with different quantities of water in the bottle.
20 litres of water is too much to lift.
0.1 litre of water won't get you very far
somewhere in between is optimal

Use your nose cone as a small parachute to deploy a bigger parachute packed into the cone. or put roter inside nose cone and come back like a helecopter

smear some soap inside the neck of the bottle, the soap will breakdown surface tension of the water so it can exit faster, you don't want foam or bubbles though.

Experiment with different diameter neck diameters. Rockets do it to increase ejection velocity, should also work for a bottle rocket.

Pressurize with hydrogen as it has the highest molecular velocity thus giving higher exahust speed

Use hot water rather than cold as it will cause the air to heat and expand thus giving slighly more pressure

i will stop now

good luck

[jhendriks87]

How did your rocket go?

[SievertChaser]

Messaggio originale di jhendriks87:

How did your rocket go?

Best necro ever; fully supported.

[jhendriks87]

Messaggio originale di dennis.danilov:

Messaggio originale di jhendriks87:

How did your rocket go?

Best necro ever; fully supported.

Haha well we put alot of effort into helping the bottle rocket design :) was just wondering how it went haha.

[Habesha Capt_Joshua]

Messaggio originale di jhendriks87:

How did your rocket go?

Well we were under a HUGE time constraint mainly because we had other physics projects due, so we ended up building a cheap rocket with virtually no quality. On launch day the cheap plastic launcher that my teacher was using broke and no rocket lasted more than 6 seconds. Sooo in all the whole project was a disaster.

But next year we will be launching. Hopefully things will go according to plan then.

[SievertChaser]

Messaggio originale di Habesha Capt_Joshua:

Messaggio originale di jhendriks87:

How did your rocket go?

Well we were under a HUGE time constraint mainly because we had other physics projects due, so we ended up building a cheap rocket with virtually no quality. On launch day the cheap plastic launcher that my teacher was using broke and no rocket lasted more than 6 seconds. Sooo in all the whole project was a disaster.

But next year we will be launching. Hopefully things will go according to plan then.

Tell the teach to research Launch Stability.

[Acestins]

Im pretty sure your fins wont do you jack if your rocket itself isnt powerful. Just make cardboard fins that have a lot of surface area.