measurement units

Discussions about rockets, construction materials, adhesives, nozzles, nosecones and fin design.
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Tim Chen
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Re: measurement units

Post by Tim Chen »

I think that the ideal system for a multiple stage rocket is to use smaller nozzles on the boosters but to use launch tubes to get them moving faster on liftoff. I've thought about doing a t-nozzle design for the best of both worlds. The thing with multi-stage is that you lose energy to drag if you go too fast so you want the burn as long as possible and you want to be as high as possible before staging. I think a combination of a launch tube and t-nozzle would be perfect.
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Re: measurement units

Post by da-water »

what is a t-nozzle??
i've already read it in my forum but i didn't understand what it is...

you wrote "liftoff".. i often read words such that..
i think they speak about the different parts of the flight..
could someone make a list of these words with a small explanation please??

thx
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Tim Chen
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Re: measurement units

Post by Tim Chen »

da-water wrote:what is a t-nozzle??
i've already read it in my forum but i didn't understand what it is...

you wrote "liftoff".. i often read words such that..
i think they speak about the different parts of the flight..
could someone make a list of these words with a small explanation please??

thx
Hey there! I can help!

A "T-nozzle" is a piece that goes inside the rocket and is designed so that when the rocket starts to thrust that the piece moves down into the bottle "mouth" opening and makes the opening smaller.

The way this works is that the "t-nozzle" rests on the tip of the launch tube pipe inside the rocket when you fill it with air on the ground. When you launch the rocket, the thrust comes from pushing the launch tube out of the mouth of the bottle. The full size mouth of the bottle pushes with the force of a 22mm nozzle on the launch tube and thrust is quite large. When the bottle reaches the tip of the launch tube, the "t-nozzle" tries to come out the bottle with the launch tube, but it is too wide at the top (it is shaped like the letter 'T') and so the t-nozzle blocks the mouth of the bottle. A hole drilled through the T-nozzle is the only path for the water to come out and therefore this hole becomes the nozzle diameter.

The result is that when you launch the rocket, the nozzle size is 22mm and when the rocket has accelerated to the end of the launcher the nozzle size is reduced by the t-nozzle piece to a much smaller size, giving a sustained thrust.
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Re: measurement units

Post by Tim Chen »

Oops. I forgot to explain that "liftoff" is the part of the flight when the rocket first leaves the ground. It lifts itself off the ground... "lift-off". :lol:
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Re: measurement units

Post by da-water »

thanks.. there are other words such "takeoff" ... is there any topic that speaks about this in the forum?? about all the phases of rocket's flight (takeoff, thrust phase..)??
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Re: measurement units

Post by Tim Chen »

da-water wrote:thanks.. there are other words such "takeoff" ... is there any topic that speaks about this in the forum?? about all the phases of rocket's flight (takeoff, thrust phase..)??
I don't think we have a topic like that. We should start one and call it a water rocket "glossary". What would be cool is we could explain where the terms come from, like the story of the Clarke Cable Tie launcher or the Robinson Coupling!
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Re: measurement units

Post by da-water »

yes, good idea!
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Re: measurement units

Post by da-water »

this is the CP Software... tell me if you like it and if there are mistakes..


p.s.: i'm not sure about the "Xr" parameter to be written right.. i had to reduce the sentence because i didn't have enough space.. tell me if it is wrong..
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D.D. ROCKETS

if you don't uderstand what I wrote, tell me it and i'll write better the same thing !!! :D
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Tim Chen
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Re: measurement units

Post by Tim Chen »

da-water wrote:this is the CP Software... tell me if you like it and if there are mistakes..


p.s.: i'm not sure about the "Xr" parameter to be written right.. i had to reduce the sentence because i didn't have enough space.. tell me if it is wrong..
Help! The link doesn't work.
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D.D._ROCKETS_CP_Software_1.2.zip
(59.71 KiB) Downloaded 400 times
Tim Chen
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Re: measurement units

Post by da-water »

really??all italian people have downloaded it and the link works..


try again...
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D.D. ROCKETS

if you don't uderstand what I wrote, tell me it and i'll write better the same thing !!! :D
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Re: measurement units

Post by xenon »

Tim Chen wrote:
da-water wrote:this is the CP Software... tell me if you like it and if there are mistakes..


p.s.: i'm not sure about the "Xr" parameter to be written right.. i had to reduce the sentence because i didn't have enough space.. tell me if it is wrong..
Help! The link doesn't work.
Try choosing the "print view" for this page and the link comes up as whole. Maybe this is a "bug" that the admins can fix.
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Re: measurement units

Post by da-water »

try here once again...
D.D. ROCKETS

if you don't uderstand what I wrote, tell me it and i'll write better the same thing !!! :D
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Tim Chen
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Re: measurement units

Post by Tim Chen »

da-water wrote:try here once again...
Oops. Sorry. It was my fault. I was trying to download from school and that site is blocked. It worked from home.
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Re: measurement units

Post by da-water »

lol.. so? do you like it??
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if you don't uderstand what I wrote, tell me it and i'll write better the same thing !!! :D
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Re: measurement units

Post by Tim Chen »

da-water wrote:lol.. so? do you like it??
I finally had a chance to experiment with your software. It took me a while to figure out the "readme" was in two languages in the same window. I expected the text would change when I clicked on the flag for english.

Well done on the program! It's very good. I can't say if the results are accurate because I have no other way to test, but it seems to work nicely and produces sensible results. I will definitely make use of this.

I hope you will expand it to multiple stages as well.

Thanks for making this program available!
Tim Chen
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