Angled tube fin rocket

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Is Andrew Off The Deep End This Time?

  • Yes, He's From Texas What Do You Expect?

  • No, He's From Texas, NASA Is There

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accooper

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OK, I love tube fin rockets 8 or more tubes. But I came upon an idea . How would it effect stability if I put a transition cone at the base of the rocket and glued the tubes to the transition at an angle.

Simroc won't allow this, neither will Open Rocket.

Any feelings on this?

Andrew
 
Got an itch to try something? My moto is "Scratch it" I actually thought about this.Not the exact same idea but close. I thought about having the tubefins them selfs cut on an angle. I got his idea from the left over piece that I cut out of the Snarky belly tube.
 
As long as you have a reasonable margin of error (big tubefins, etc) I don't see any reason why this wouldn't work.


As long as you take pictures. If there's not a camera present, it's guaranteed to fail.
 
I think the tubes will be less effective than if they were straight, but the cone should help stability somewhat.

The best thing to do is to try it, but in a fairly small scale (A or B motor) and see how it works. I would think it would work OK though.
 
I think that drag would go through the roof (even by tubefin standards), but stability should be quite good.
 
Everyone is missing the point with Andrew. He is currently vying for the title from the Alamo Rocketeers, permanently held by Stu Young, of "most likely to make spectators run screaming for their lives". He's made a few respectable attempts but he's just not in Stu's league.

Nobody is.
 
Performance, schmorance. Sim it with regular tube fins and give it a try.
 
Well as I remember, some of the Apollo rockets had huge diverters to try to blow air under the rocket and reduce a little of the base drag. I would suspect this would have a similar effect, or at least not be as bad as some people predict.

Either way, GO FOR IT! It should look absolutely unique.
 
Any feelings on this?
One of the concerns I have is that it will oscillate. Here's why I think that. This thing will stay pointed straight up as long as all the lateral forces from the tube fins remain balanced. But, if it gets a little crossways in flight, I could see some of the tubes getting more "traction" than those on the opposite side with the result that the thing gets a very large AoA. I suspect it won't completely loop, because once it gets nearly 90° AoA, if the cardboard cutout is stable, then it will correct. But it probably won't dampen out quickly. So I can see it wiggling on the way up.

Doug...not an aerodynamicist...

.
 
I really don't think that will be the case. I'd guess that it will fly fairly straight. It's hard to say for sure though. As I said, the way to go is a small-scale test flight. A wind tunnel would work too...
 
I still say sim a baseline and then try it. The whole Earth is my wind tunnel. :wink:
 
I guess my question would be - how large are you planning on making this beast. If small, build it and swing test it. If large, build a small scale version and swing test that. Also, are you talking about putting the large end of the transition at the base of the rocket or the small end. I could see trying either one. If the large end is down, build it about BT-20. If small is down, build it about BT-50, 55 or 60. Either way, if you can get the small scale version to fly in a stable config, as long as the CG of the larger version is in the same place as the smaller version, the larger version will be stable as well.
 
Got an itch to try something? My moto is "Scratch it" I actually thought about this.Not the exact same idea but close. I thought about having the tubefins them selfs cut on an angle. I got his idea from the left over piece that I cut out of the Snarky belly tube.



You mean something like this?

Six BT 50s wrapped around a BT 55.

Take note; even with this small angle the rocket spins so fast its performance is severely degraded. Can’t even launch it with a D or an E as it spins so fast it becomes unstable.

th_12-14-10-2002.jpg


th_12-14-10-2003.jpg
 
No, I don't think so.....

From what I understand; he wants to glue the tubes so that they are parallel to the transitions slope. They would be facing outward looking similar to the X-29 jet
https://en.wikipedia.org/wiki/Grumman_X-29


JD


You mean something like this?

Six BT 50s wrapped around a BT 55.

Take note; even with this small angle the rocket spins so fast its performance is severely degraded. Can’t even launch it with a D or an E as it spins so fast it becomes unstable.

th_12-14-10-2002.jpg


th_12-14-10-2003.jpg
 
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