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After @Dotini ‘s success, I am hoping to build on his sucess.
so this will be a mixture of recovery techniques
https://patents.google.com/patent/US6926576
http://www.gorgerocketclub.com/wp-content/uploads/2017/03/Backslider.pdf
a key on these is that some models that had imparted spin (unintentionally, I think) successfully “backslid “ until they stopped spinning at which point they went ballistic (literally.) I theeeeeenk that the spinning resulted in Horizontal Spin effect, which is half the battle.
Sooooo, what if we could keep it spinning? Looks like all the rockets in the above articles had normal planar fins. Perhaps some were canted a bit, but looks like that was unintentional, and canted fins won’t maintain a spin once the rocket goes horizontal anyway.
Edit: okay, @Rktman just showed me that was wrong
I have done horizontal spin successfully, but for the most part I did a James T. Kirk Kobayasihi Maru maneuver (to quote McCoym “He cheated.”) I dumped the nose cone or used it as a booster segment. I am not sure that segments that I successfully did horizontal spin on weren’t STILL stable (they would probably have lawn darted if they HADN’T spun, but they weren’t EXTREMELY stable rockets.
@Dotini has performed a bit of magic getting HIS rocket to horizontal spin WITHOUT a CG shift or other configuration change, just using a forward blowhole of the ejection charge to momentarily “stun” the smooth forward stabile trajectory, throwing the angle of attack from normal near zero to likely something likely 30 degrees or more off axis. The rocket begins to fall, and it’s a race to see which aerodynamic force will kick in first.
The EXPECTED result is that tail/fin drag vs pointy heavy nose OBVIOUSLY will pull the model nose down and it will auger in.
the HOPED result is that the “funky fins” will get this to start rotating, and because of the positive feedback (what starts as a randomly tumbling rocket with the right fin structure is amazingly easy to start rotation, and as it starts rotating AND falling goes more horizontal which brings it into a positive feedback loop with eventual PERFECT alignment for BOTH maximal spin AND maximum drag.)
the QUESTION is WILL IT GLIDE? (Calling @Rktman !) of course, I am not sure how the backsliders in the above links glided either.
on the other hand, the StovePipe was a rotating glider as well, the problem was to keep it rotating
http://www.spacemodeling.org/jimz/eirp_56.htm
Anyway, starting with three pairs of tube fins (going with 6 tubes around a central tube of same diameter.) aligning two tube fins in pairs is easy, and the pairs will automatically align with the long axis of the central core and provide automatic perfect spacing.
I am going to start with a short body tube base, I will add a length of body tube to it to get at least a 30 to 1 length to tube diameter ratio.
after seeing where @Dotini ‘s rocket took a crimp (not sure the cause, but suspect bent on impact) I may beef that segment up.
(just for fun I found somebody actually made a model of the Kobayashi Maru from the limited images from the Abrams movie.
I threw a pic in just for fun. Google it under shopping and you’ll find it.)
so this will be a mixture of recovery techniques
https://patents.google.com/patent/US6926576
http://www.gorgerocketclub.com/wp-content/uploads/2017/03/Backslider.pdf
a key on these is that some models that had imparted spin (unintentionally, I think) successfully “backslid “ until they stopped spinning at which point they went ballistic (literally.) I theeeeeenk that the spinning resulted in Horizontal Spin effect, which is half the battle.
Sooooo, what if we could keep it spinning? Looks like all the rockets in the above articles had normal planar fins. Perhaps some were canted a bit, but looks like that was unintentional, and canted fins won’t maintain a spin once the rocket goes horizontal anyway.
Edit: okay, @Rktman just showed me that was wrong
I have done horizontal spin successfully, but for the most part I did a James T. Kirk Kobayasihi Maru maneuver (to quote McCoym “He cheated.”) I dumped the nose cone or used it as a booster segment. I am not sure that segments that I successfully did horizontal spin on weren’t STILL stable (they would probably have lawn darted if they HADN’T spun, but they weren’t EXTREMELY stable rockets.
@Dotini has performed a bit of magic getting HIS rocket to horizontal spin WITHOUT a CG shift or other configuration change, just using a forward blowhole of the ejection charge to momentarily “stun” the smooth forward stabile trajectory, throwing the angle of attack from normal near zero to likely something likely 30 degrees or more off axis. The rocket begins to fall, and it’s a race to see which aerodynamic force will kick in first.
The EXPECTED result is that tail/fin drag vs pointy heavy nose OBVIOUSLY will pull the model nose down and it will auger in.
the HOPED result is that the “funky fins” will get this to start rotating, and because of the positive feedback (what starts as a randomly tumbling rocket with the right fin structure is amazingly easy to start rotation, and as it starts rotating AND falling goes more horizontal which brings it into a positive feedback loop with eventual PERFECT alignment for BOTH maximal spin AND maximum drag.)
the QUESTION is WILL IT GLIDE? (Calling @Rktman !) of course, I am not sure how the backsliders in the above links glided either.
on the other hand, the StovePipe was a rotating glider as well, the problem was to keep it rotating
http://www.spacemodeling.org/jimz/eirp_56.htm
Anyway, starting with three pairs of tube fins (going with 6 tubes around a central tube of same diameter.) aligning two tube fins in pairs is easy, and the pairs will automatically align with the long axis of the central core and provide automatic perfect spacing.
I am going to start with a short body tube base, I will add a length of body tube to it to get at least a 30 to 1 length to tube diameter ratio.
after seeing where @Dotini ‘s rocket took a crimp (not sure the cause, but suspect bent on impact) I may beef that segment up.
(just for fun I found somebody actually made a model of the Kobayashi Maru from the limited images from the Abrams movie.
I threw a pic in just for fun. Google it under shopping and you’ll find it.)
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