Streamlined rocket?

[eafindme]

Hi, everyone.
I'm newbie to build my first bottle rocket.
I designed a rocket sample. Pls refer to the attached picture. The fins is excluded.
I used 2x1.5L soda bottle to build this. One of the bottle is cut to fit the nose. I kept he rocket as streamline as possible.
Can anybody give me some comments? Is that design effective to reduce the air drag to minimum?

[chriswaterrockets]

Hey there and welcome to the forum!
I think your rocket looks good. I'm sure drag won't be a probblem. If this is your first rocket, you shouldn't worry to much about such little things like drag. Rather try to get the rocket to be stable first. That means you might have to add some weight to the nosecone.
Just go out and try it out and let us know what you find out!

Cheers

[U.S. Water Rockets1]

eafindme,

Yes, you have done a great job of making your rocket as streamlined as possible. The only thing you could do to this design is to smooth out the tail section, such as removing the threads and the "grip" part by filing them off. This requires that you devise a launcher that holds the water rocket by the internal surface of the bottle.... and this is something few people have done successfully. We have a design on our website we call the "Twist Lock Launcher" that works very well, but requires a lot of work to build.

Keep up the great work!

[eafindme]

Not bad, the twist lock launcher looks great, but need a lot of works indeed.
If I alter the nosecone like an aircraft (adding some sharper cone), does it further reduce the drag while adding more weight to the nosecone?

[U.S. Water Rockets1]

Not bad, the twist lock launcher looks great, but need a lot of works indeed.
If I alter the nosecone like an aircraft (adding some sharper cone), does it further reduce the drag while adding more weight to the nosecone?

Really sharp points are only effective at supersonic speed rockets. Elliptical noses are fine at the speeds reached by water rockets, so you probably do not have to worry about making the noses more pointed.

The only other thing you can consider is making your rocket longer by splicing bottles together or using longer bottles or tubes for the rocket bodies. This doesn't make the rocket more aerodynamic, but it increases the volume without increasing the frontal area and this helps reach higher altitudes.

[eafindme]

Oh, splicing bottles together. Thanks for your information but I have no idea how to build it. Anyway, I'll try my first rocket. I hope it works.

[Tim Chen]

Oh, splicing bottles together. Thanks for your information but I have no idea how to build it. Anyway, I'll try my first rocket. I hope it works.

You need to get some PL Premium glue! You can splice anything with that!!!

[eafindme]

i tested my rocket. i don't know the pressure and the distance my rocket goes. all i know is i can't see it until i heard the sound of my rocket drop onto the road, maybe 100 meters away and my rocket is damaged.

[Tim Chen]

i tested my rocket. i don't know the pressure and the distance my rocket goes. all i know is i can't see it until i heard the sound of my rocket drop onto the road, maybe 100 meters away and my rocket is damaged.

I have a construction hardhat that I wear when I launch because many times I lose sight of the rocket. When that happens I duck and brace for impact until I hear it land. If I don't hear a crash after 10 or 20 seconds I look for the parachute. LOL!

[eafindme]

I made a lot of improvement. I added some weight at the nose with plasticine. I also stuck some fins and tried to reduce the weight of the rocket to minimum (around 150g). I uploaded the picture of my rocket.
If I use stationery tape which has smoother surface instead of using masking tape, can it affect the performance of the rocket? Can somebody give me some better ideas on my design?

[dongfang]

Hi,

Your smoothing efforts look perfect to me; much better than my own rockets.

I would consider larger, longer rockets. Find some bottles that are easy to splice. I use some where the top of one fits right into the cut-off bottom of the next one. I will try a rocket of 10 or 12 of those soon....

Regards
Soren

[eafindme]

I put a lot of effort on it because I will take it to water rocket competition which is organized by my school. Spicing bottles is a good idea, maybe I'll build it for the next time.
Since this is my first time I build water rocket, that is enough to use a 1.5L bottle.
I'll like to see your rocket if you spice 10 to 12 bottles successfully!

[Team Seneca]

I made a lot of improvement. I added some weight at the nose with plasticine. I also stuck some fins and tried to reduce the weight of the rocket to minimum (around 150g). I uploaded the picture of my rocket.
If I use stationery tape which has smoother surface instead of using masking tape, can it affect the performance of the rocket? Can somebody give me some better ideas on my design?

You can't get much more streamlined than that! Good work!

[eafindme]

Hi, everyone. I got a good news. I have captured not much photos that day but you should see a large differences of my design with other competitor. I and my group win the first place in rocket (far range) and parachute competition. Since this is the first rocket competition organized by my school, there is not much response from the students. But I believe that more students will take part in this competition for the next time because they seem have a lot of fun while watching the rockets launched. I'm very satisfies the performance of my rocket. Actually, I know it can perform better by pump in more pressure. It flies about 3/5 or roughly 120 meters of my school's field while I pumped it at 60psi (upper limit is 140psi).

[eafindme]

And sorry for large images. I forget to convert it into smaller ones.