Quantcast

Here's a weird one

The Rocketry Forum

Help Support The Rocketry Forum:

neil_w

Marginally Stable
TRF Supporter
Joined
Jul 14, 2015
Messages
11,090
Reaction score
3,942
Location
Northern NJ
There is no reason for this oddball idea other than that it popped into my head:

Here's why it's weird:


There is an empty stuffer tube down the length of the airframe. Powered by one motor in each pod. It would still deploy from the front, using gas ducted from the pods and what looks like a typical rear deploy setup (chute wrapped around the inner tube), except coming out the front.

I haven't yet decided if this is "good weird" or just "stupid weird", although I'm probably leaning towards the latter. Not sure if there's a clever way to exploit it, or if it's an idea best left behind.

The launch lug could be internal. Any other fun things to do with it?

hollow_front.png


hollow_side.png
 

TRFfan

Well-Known Member
Joined
Aug 5, 2015
Messages
1,211
Reaction score
2
There is no reason for this oddball idea other than that it popped into my head:

Here's why it's weird:


There is an empty stuffer tube down the length of the airframe. Powered by one motor in each pod. It would still deploy from the front, using gas ducted from the pods and what looks like a typical rear deploy setup (chute wrapped around the inner tube), except coming out the front.

I haven't yet decided if this is "good weird" or just "stupid weird", although I'm probably leaning towards the latter. Not sure if there's a clever way to exploit it, or if it's an idea best left behind.

The launch lug could be internal. Any other fun things to do with it?
Is this design in openrocket?
 

BABAR

Builds Rockets for NASA
TRF Lifetime Supporter
TRF Supporter
Joined
Aug 27, 2011
Messages
7,704
Reaction score
2,625
If the inside tube diameter is jus right could launch off a mini rail.
I am curious how SIM programs will handle that nose. Given length of the inside tube I do NOT THINK it will work as a tube fin so effectively a blunt flat nose. Would anticipate a heck of a lot of forward drag which would not be good for CG/CP relationship5
 

neil_w

Marginally Stable
TRF Supporter
Joined
Jul 14, 2015
Messages
11,090
Reaction score
3,942
Location
Northern NJ
Oh wow. Any idea when it will come out?
Nope.

If the inside tube diameter is jus right could launch off a mini rail.
I am curious how SIM programs will handle that nose. Given length of the inside tube I do NOT THINK it will work as a tube fin so effectively a blunt flat nose. Would anticipate a heck of a lot of forward drag which would not be good for CG/CP relationship5
I feel confident in saying that the sims wouldn't have the slightest idea what to do with this. :)
 

cavecentral

Well-Known Member
Joined
Jul 1, 2011
Messages
3,129
Reaction score
25
I like it. I planned to do some ramjet looking rockets for a 5.5" using a 3" or smaller cone and a valley instead of transition.

See if yours whistles or makes any other sounds.
 

modeltrains

Well-Known Member
Joined
Jun 29, 2011
Messages
1,371
Reaction score
247
... and what looks like a typical rear deploy setup (chute wrapped around the inner tube), except coming out the front.
Maybe, unless that's already been tried, build it as a practical experiment to see what happens with that?
 

Skp

Well-Known Member
Joined
Mar 29, 2013
Messages
227
Reaction score
1
I like it, I like it a lot.
 

K'Tesh

OpenRocket Chuck Norris
TRF Supporter
Joined
Mar 27, 2013
Messages
14,849
Reaction score
1,257
I'll put a "Ditto" to Skp's comment. and add "Go For It!!!"
 

K'Tesh

OpenRocket Chuck Norris
TRF Supporter
Joined
Mar 27, 2013
Messages
14,849
Reaction score
1,257
Naming idea... "Hollow Pursuits", or in honor of it's pair of motors... "Hollow Pairsuits"
 

fyrwrxz

latest photo
Joined
Jun 6, 2011
Messages
6,580
Reaction score
55
I vote it should be called...wait for it......wait for it......"Open Rocket" (badaboom- tissss air drums)
 

K'Tesh

OpenRocket Chuck Norris
TRF Supporter
Joined
Mar 27, 2013
Messages
14,849
Reaction score
1,257
I vote it should be called...wait for it......wait for it......"Open Rocket" (badaboom- tissss air drums)
I feel that fyrwrxz has a good chance of winning this...
 

neil_w

Marginally Stable
TRF Supporter
Joined
Jul 14, 2015
Messages
11,090
Reaction score
3,942
Location
Northern NJ
I vote it should be called...wait for it......wait for it......"Open Rocket" (badaboom- tissss air drums)
That almost makes me want to build it, just for the name.

However, this design is nowhere close to a build, it's just an idea. I feel like the one I posted up there doesn't really exploit the open tube well enough, although I'm not sure exactly what else there is to do with it.

I certainly encourage anyone else who wants to have a go at it, though...
 

Swissyhawk

Well-Known Member
Joined
Sep 11, 2013
Messages
260
Reaction score
1
How about putting a smaller rocket in the open tube and airstarting it?
 

les

Well-Known Member
TRF Supporter
Joined
Jan 20, 2009
Messages
2,811
Reaction score
421
I would be concerned that the air will not be able to freely flow through the long open center tube....
 

Incongruent

Well-Known Member
Joined
Oct 25, 2016
Messages
1,735
Reaction score
5
I would be concerned that the air will not be able to freely flow through the long open center tube....
I think it'll work enough; even if you imagine it as a flat surface it's not too bad.
Except for shock waves (at transonic speeds), I'm not sure what would be impeding the airflow. Can you enlighten me on this point?

I think the pods should become gliders and the center tube should flutter down (some small control surface to bring it out of a ballistic recovery path.)
 

Cabernut

Well-Known Member
Joined
Oct 15, 2015
Messages
1,384
Reaction score
2
Has a sort of SR71 feel to it. I vote "Open Rocket" for the name. Just too cool.
 

GlenP

Well-Known Member
Joined
Oct 4, 2014
Messages
2,200
Reaction score
484
Converging diverging transitions on the inner through tube, like on the diamond cutter, to see if you can get it to whistle.
 

les

Well-Known Member
TRF Supporter
Joined
Jan 20, 2009
Messages
2,811
Reaction score
421
I think it'll work enough; even if you imagine it as a flat surface it's not too bad.
Except for shock waves (at transonic speeds), I'm not sure what would be impeding the airflow. Can you enlighten me on this point?

I think the pods should become gliders and the center tube should flutter down (some small control surface to bring it out of a ballistic recovery path.)
There is air friction (drag) over every surface. You now have a long "tunnel" with 360 degrees of drag. I'm thinking the air flow through the tube may slow enough due to the drag that it may act as a virtual "plug". I doubt it will completely block the air, but will it create enough resistance that the airflow will then take the easier path around the outside?

I'm not an expert and just providing my :2:
 

Incongruent

Well-Known Member
Joined
Oct 25, 2016
Messages
1,735
Reaction score
5
There is air friction (drag) over every surface. You now have a long "tunnel" with 360 degrees of drag. I'm thinking the air flow through the tube may slow enough due to the drag that it may act as a virtual "plug". I doubt it will completely block the air, but will it create enough resistance that the airflow will then take the easier path around the outside?

I'm not an expert and just providing my :2:
Thanks, that makes sense.

It might minimize base drag as well, which could be both good (less drag) and bad (less stable). So in this case some of the air would be pulled out the bottom as well.
 

dhbarr

Amateur Professional
Joined
Jan 30, 2016
Messages
6,985
Reaction score
1,436
LOTS of body lift on this model, and I'm guessing gusts would be particularly unfriendly.
 

fyrwrxz

latest photo
Joined
Jun 6, 2011
Messages
6,580
Reaction score
55
I'm tempted to try a mock up just to see if I can get it to whistle......,maybe a reed inside?
 

Nytrunner

Pop lugs, not drugs
TRF Supporter
Joined
Oct 15, 2016
Messages
7,761
Reaction score
3,389
Location
Huntsville AL
I like the idea of a rail running through the middle. Although with most of Neil's designs, I tend to get ahead of myself and immediately imagine them on 38mm motors.

Did this evolve out of your starfighter/rocket discussion with the incomplete ring fin?
 

tomsteve

Well-Known Member
Joined
Feb 24, 2014
Messages
894
Reaction score
257
but....but....
only 2 pods for motors when theres room for MORE POWER!?!?!?!:cool:
 

neil_w

Marginally Stable
TRF Supporter
Joined
Jul 14, 2015
Messages
11,090
Reaction score
3,942
Location
Northern NJ
I like the idea of a rail running through the middle. Although with most of Neil's designs, I tend to get ahead of myself and immediately imagine them on 38mm motors.
I patiently await seeing an upscale of any of them (seriously).

Did this evolve out of your starfighter/rocket discussion with the incomplete ring fin?
No, this one just came out of the blue; although the first iteration rather closely resembles Expjawa's Sagittarius Arrow, which I love and was thinking of actually building at some point.

Generally, once a new design idea gets lodged in my head, I am obligated (to maintain my sanity) to enter it into OR and see how it looks. If it's interesting, I'll spew it out into the forum-o-sphere, at least until someone raises an objection.

Once in a while such an exercise actually leads to a build (e.g. Starship Avalon).
 

mjennings

Well-Known Member
Joined
Jan 18, 2009
Messages
1,581
Reaction score
19
Les is right the friction between air and rocked down the tube and the boundary flow will essentially at some point act like a flat plate in the tube. That's not to say that this wouldn't work, just don't expect it to get as high as a the same rocket with a solid NC. It is the same reason that you do not see very long tube fins, at some point the length reduces the effective and they don't work.
 
Top