Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: B3YT on May 20, 2008, 04:50:01 PM
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thought . If the CoG is important wouldn't the pushing of the rocket tail cuase it to move the CoG . Making it nose up at luanch decreasing range?
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given the large amount of cartoon pilot brainpower that has been put into this post and has done nothing but spinwheels................... ............................. .......... i have 2 words on how to solve this............ Myth Busters !!!!!!!!!!!!!!!!! :D
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This link has excellent photos (much better than I could produce) of rocket stability principles.
http://www.rockets4schools.org/education/Basic_Rocket_Stability.pdf (http://www.rockets4schools.org/education/Basic_Rocket_Stability.pdf)
This photo taken from NASA's web site...
(http://i255.photobucket.com/albums/hh121/purplehaze835/rktcock.gif)
Rather cool night launch photo showing the weather vane effect....
(http://i255.photobucket.com/albums/hh121/purplehaze835/nightlaunch.jpg)
Notice the wind blowing smoke to the right and rocket turning into it.
Hope these help and granted they are vertical launch rockets but all the principles are the same.
Strip
ow that makes my head hurt
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Your spelling makes my head hurt.
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ha ha ha
:furious :furious :furious
:furious :furious :furious
:furious :furious :furious
:furious :furious :furious
:furious :furious :furious
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I believe I see what you are saying, Strip.
At a stand still there is no wind affecting the rocket's trajectory, but while moving forward there is some acting on it because of the motion. Since the rocket turns into the wind slightly, it lowers the trajectory slightly which makes a big difference over all? I will try to draw a picture as well.
Poorly drawn picture.
(http://img246.imageshack.us/img246/3235/trajectorymodifiedbywinkh0.png)
I hope this helps.
The reverse is true for it moving backwards. It wants to go into the wind again, raising the trajectory from 23 degrees to something closer to 45, this makes it travel farther.
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If a door had a rocket attached to it, inline with the door's width (not thickness), and you lit the rocket.. In a perfect world, the rocket would have no effect on the door's swing. If the door was set on such a perfect set of bearings, nudging the door with your index would swing the door - the rocket thrusting away would have no effect.
(http://farm3.static.flickr.com/2103/2510599054_e693950ba2_o.png)
It's the same thing with the 251 rockets, except the finger nudge is wind, and the door's swinging axis is the rocket CoG, far forward.
If you drop a bowling ball, and the below contraption from a speeding platform, the latter will have a different trajectory thanks to the tail feathers rotating the contraption around the cog somewhere in the bowling ball.
(http://farm3.static.flickr.com/2064/2509762757_5d2b7c2821_o.png)
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You and your fancy pictures :D.
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hehe.. not as fancy as yours or Strip's :P
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wonder why no one has commented on my statement. here's how it works. The halftrack is moving in a 0deg vector correct. the rocket on the other hand is firing at a 25deg vector to the halftrack . as it leaves the cage wouldn't the cage moving at a -25deg vector push the tail down causing an unstable luanch, causing the rocket to tumble in it's first few moments of flight? or would the cage moving away from the rockets head cause it to droop on luanch? picture to follow
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Isn't it possible for a couple of these things to be happening at the same time?