Lakeroadster's Yoko Tsuno 27 Rocket

[lakeroadster]

Marc Caron over at the Estes FB page posted up a photo of a rocket from Yoko Tsuno 27. I have no idea what Yoko Tsuno is... looks like a comic book of some sort.

Marc was curious about designing a model rocket, based on that design.

I made an Open Rocket model that "kind of" simulates the design.

I then made a CAD Model that "kind of" simulates the design, but with a flow through fin design.

My question to you folks is, with the flow through fin design that also has fin tubes, do you think it will be stable due to not having fins in both the X and Y planes?

I haven't designed all the bits and bobs that make it look neat... just trying to determine if it'll fly first.

 

[mbeels]

Really neat design! I love these kind of futuristic space / sci-fi kinds of designs.

I'm no expert, but I think that the length/diameter ratio will be too high for the tubes to effectively stabilize the rocket. Perhaps it is something worth mocking up and doing a swing test.

 

[Scott_650]

Hmm...I’d say use those hemispheric “tank” structures, moved more towards the centerline on the dorsal and ventral sides, to create some balance. Or use the “W” shape of the forward edges of the body fairing on the comic book version to create dorsal and ventral intake structures. Or just add enough nose weight

 

[mbeels]

It also may benefit quite a bit from the base drag, which looks like it ought to be pretty high.

 

[neil_w]

With both stages in place, those tube fins look too long. Above a certain aspect ratio air stops flowing through them and they stop providing stability. I don't know what that ratio is, but those are far longer than tube fins you see on typical rockets.

I think tube fins (in general) provide stability in both axes, but I've never seen a rocket with only two tube fins, so I dunno.

 

[lakeroadster]

I'm no expert, but I think that the length/diameter ratio will be too high for the tubes to effectively stabilize the rocket. Perhaps it is something worth mocking up and doing a swing test.

With both stages in place, those tube fins look too long. Above a certain aspect ratio air stops flowing through them and they stop providing stability. I don't know what that ratio is, but those are far longer than tube fins you see on typical rockets.

I think tube fins (in general) provide stability in both axes, but I've never seen a rocket with only two tube fins, so I dunno.

Easy enough... I'll eliminate the tube fins from the booster stage.

 

[dhbarr]

I think once you have the pods on you'll be good to go. None of those tubefins will allow much flow, but the base drag will be enormous.

 

[Daddyisabar]

Looks like you can flair out the bottom a bit with a shroud - like an SR 71 or Sunward Desert Fox. The more flair the better. Staged will have variable CP. Don't see where the full air through helps because it is so far forward. But Mindsim is dangerous and it is good to have faith in the machines. Many machines on IX.

 

[lakeroadster]

Looks like you can flair out the bottom a bit with a shroud - like an SR 71 or Sunward Desert Fox. The more flair the better. Staged will have variable CP. Don't see where the full air through helps because it is so far forward. But Mindsim is dangerous and it is good to have faith in the machines. Many machines on IX.

Did a bit more goofing around with model and sim's. Ironic Daddyisabar that you mention the SR-71. I added a vertical stabilizer, and some lower "skid" fins.. and thought "This 1st stage kind of looks like an SR-71".

Would also be a good candidate for a triple motor cluster design, maybe (3) C6's for boosters and a C6 single stage? I'd still build it though for 24mm's and used adapters for the C's.

Oh, and for the spherical fuel tanks...... we took our Christmas tree down today... plastic ornaments... perfect.

 

[Daddyisabar]

You can't go wrong with Christmas ornaments or like SHROX and his ping pong balls. A staged booster would be cool.

 

[Nytrunner]

The booster needs something in the vertical orentation. Air will divert around those balls more than stabilize the rocket.

 

[lakeroadster]

The booster needs something in the vertical orentation. Air will divert around those balls more than stabilize the rocket.

Hmmm.... Think so?

I figured the base drag is going to be so much that the booster stage wouldn't need any vertical fins.... but that once the booster stage is ejected all that drag would be gone and the 1st stage needed the vertical fins.

Right,
Wrong,
or none of the above?

 

[neil_w]

There will be some base drag but I for one would have no idea how to estimate how much. I remember @Flyfalcons' amazing Flying V rocket survived almost purely on base drag, which I never would have guessed, but it actually had a pretty thick and wide profile at the back. Your design here has less, and I have no idea what the effects of those ping pong balls will be.

Mindsim says.... Segmentation fault, job killed.

 

[lakeroadster]

Segmentation fault, job killed.

I need a decoder ring...

 

[Nytrunner]

Agreed with Neil. The design above has very little base area, and the profile is more like a fat wing than blunt back end. Additionally, depending on the stacked CG, the sustainer fins may be a destabilizing force.

You could always build it anyway, swing test it with the booster, and if it behaves squirrely, turn it into a really nice shelf model

 

[mbeels]

Yeah, this seems like a good candidate for swing testing, or building and test flying a downscale version (such as with a 13mm motor).

 

[dhbarr]

Booster doesn't need fins IMO. Will tumble nicely a bit on burnout.

 

[SDramstad]

Just build it! It will be cool if it works and if it doesn’t. I mean, isn’t this why we set up a “far” pad????

 

[lakeroadster]

Just build it! It will be cool if it works and if it doesn’t. I mean, isn’t this why we set up a “far” pad????

It is indeed.

I'm a Lone Wolf.... just me and my better half, no club, no spectators. So it's a "It'll either go... or blow.... either way it'll be spectacular" event.

 

[mbeels]

I'm curious about the original cartoon rocket. It's hard to tell from the pictures, but does the comic book original have a single leading edge (not flow through)? I did some quick image searching, but didn't find any images of the rocket from the front.

I see you've got 4 current projects going, is this one "on deck"?

 

[lakeroadster]

I'm curious about the original cartoon rocket. It's hard to tell from the pictures, but does the comic book original have a single leading edge (not flow through)? I did some quick image searching, but didn't find any images of the rocket from the front.

I see you've got 4 current projects going, is this one "on deck"?

The original is not flow thru and is tapered to a point in the front.

They are all on deck... I decided to do an easier project.. so that's why the Hammerhead is in the workshop, and this one is on the drawing board.

I'm easily distracted

 

[mbeels]

I'm easily distracted

By some seriously cool designs. I'm following your threads closely, awesome stuff.

 

[jqavins]

The stability of that officially and completely beats the heck out of me. But...

There's a Rocksim feature, that OR may or may not have as well, that might help. It's a plot of the static stability margin with respect to angles of attack that vary all the way around the rocket. The single sated margin is the minimum from this this data, and looking at the picture lets you see where the rocket is lacking fin area or has more than enough.

It may turn out, for instance, that the tubes on the sustainer alone are adequate on both axes, but being too long with the booster attached means dorsal and ventral fins are needed only on the booster. I"m not saying that'll be the case - see the first sentence - just that the additional information might help.

Also, if you build it with 24 mm MMTs and want C engines, you could use C11s rather than adapters. Options, options.