Are Variable Fighters Aeronautically Feasible?

[David Hingtgen]

That's a myth. And mainly because it used old aerodynamic theories/calculations. (not surprisingly, since even most colleges today still teach theories of flight that are utter BS and easily disprovable)

[Shaka_Z]

well... according to old aerodynamic theories, bees couldnt fly... there have been breakthroughs in the last decade in terms of the understanding of how insect wings operate - bees in particular are able to warp their wings such that they are able to generate positive lift on both the up and down strokes.

in all though, I have to say that power is the principal problem with a valk. once that gets beaten, we might just see them - although I doubt they would ever be used in large numbers... more as a specops mecha, where their versatility would be an asset. remember that there are fusion reactions that dont produce hard radiation, and reactors like the bussard polywell could be made quite compact. the rest is all materials and computing power.

[anime52k8]

That's a myth. And mainly because it used old aerodynamic theories/calculations. (not surprisingly, since even most colleges today still teach theories of flight that are utter BS and easily disprovable)

again I really wish I had a better grasp of things like physics.

[DeeBot]

Actually, using classic aerodynamic models, even a Cessna can't fly. So they're just really horrible; bumblebees are so small that some different aerodynamic effects come into play. They're flying through what, to them, is like maple syrup. Turbulence, which is something normal aerodynamic design shoos off into a corner and tolerates, is exploited.

[Mr March]

Applying conventional technology to the fighter modes of the Valkyries might be a problem, especially on craft like the VF-1 which has an odd form to the ventral fuselage that may cause a lot of problems with drag or inherent instability. However, I would think that once we analyze the Valkyries as OverTechnology, the need for aeronautical feasibility becomes superfluous to a much greater degree than it is in modern aerodynamics. Valkyries have so much thrust, so much cheap power, are so efficient and have such incredible fuel economy they could probably be flying bricks and they'd work

I would think the kind of computer they must have on board a Valkyrie can handle any kind of complex fly-by-light requirements. And let's face it, with such advanced thrust vectoring engines and vernier thrusters in all modes, why even bother with traditional controls? I suppose aerodynamics do make the Valkyries more efficient than flying bricks and more responsive to control, but even the verniers can lift a Super Valkyrie off the ground (like Hikaru's VT-1 Ostrich in DYRL) and extremely high maneuverability relies on verniers anyway (like the YF-19/YF-21 seen in Macross Plus).

[talonlm]

Short answer - no.

Nonsense. The got the F-4 into the air, didn't they? There's living proof for you that if you strap a big enough engine to it, a brick will fly. A Valkyrie would be simple compared to that pig. Loaded out, it would be a drag-index nightmare, certainly, but it should be feasible, at least in fighter mode.

[d3v]

Applying conventional technology to the fighter modes of the Valkyries might be a problem, especially on craft like the VF-1 which has an odd form to the ventral fuselage that may cause a lot of problems with drag or inherent instability. However, I would think that once we analyze the Valkyries as OverTechnology, the need for aeronautical feasibility becomes superfluous to a much greater degree than it is in modern aerodynamics. Valkyries have so much thrust, so much cheap power, are so efficient and have such incredible fuel economy they could probably be flying bricks and they'd work

That ventral area is the one major compromise in the VF-1's otherwise elegant design. IRL they'd probably have to put an array of small fins and slats on the head just to smoothen out the airflow and lessen the drag in that area (give it to some F1 aerodynamicists, those guys should know a thing or to about making odd looking designs aerodynamic ).

Then again, you could simply say that the designers probably figured that the Valk would fight mostly in space and decided that drag wouldn't really be an issue.

[big F]

That's a myth. And mainly because it used old aerodynamic theories/calculations. (not surprisingly, since even most colleges today still teach theories of flight that are utter BS and easily disprovable)

Oh I did all that 20 years ago and have been out of aviation for about 17 years. So much has happened since then and training and theory is far better. They let you use computers now They made us do it with slide rules and paper and calculators. We were apprentices and they were sadistic teachers, the military way is the only way. But even back then we questioned the theory. I remember one of the guys in our group made an equation to prove that bees fly by magic, as physics said they couldn't. He now works for Boeing.

[VF-25S Full Armour]

Oh I did all that 20 years ago and have been out of aviation for about 17 years. So much has happened since then and training and theory is far better. They let you use computers now They made us do it with slide rules and paper and calculators. We were apprentices and they were sadistic teachers, the military way is the only way. But even back then we questioned the theory. I remember one of the guys in our group made an equation to prove that bees fly by magic, as physics said they couldn't. He now works for Boeing.

Sad to say, but the terrible and honest truth is that so called higher education remains a sick joke/game to this day. This applies best to engineering in general, though of course some are worse than others.

[Knight26]

Ok if this at all incoherent excuse me, I have been on duty since 0000 for a mission that just ended. Pretty much any of the mainline valkyries shown in the Macross series' could fly in their fighter modes with some tweaks. The VF-1 for example, if built in the VF-X configuration where the arms and head were faired in would probably fly fairly nicely, albeit with a very good FBW system. If similar enhancements were made to nearly all the other fighters I, as an aerospace engineer, see no reason why a flyable version would not be possible. Would they have the performance seen in the anime, dear god no, we simply do not have the materials and powerplants to allow for such a thing. Anyway my cognitive functions are rapidly breaking down, so why I am still conscious I am going to grab something heavily caffinated from the snack bar, wake myself up and head home.

[Heron]

Real World Nuclear Powered Aircraft

Interesting, no?

Nuclear Powered Article

From 1948 onward...

[JB0]

Real World Nuclear Powered Aircraft

Interesting, no?

Nuclear Powered Article

From 1948 onward...

Meh, forgot about that one.

Though they chose the utterly massive B-36. And used a partially-shielded reactor to reduce weight, as well as using direct air cooling instead of a heat exchanger.

So fission-powered FIGHTERS are still unfeasable. Nyah!

[RichterX]

Meh, forgot about that one.

Though they chose the utterly massive B-36. And used a partially-shielded reactor to reduce weight, as well as using direct air cooling instead of a heat exchanger.

So fission-powered FIGHTERS are still unfeasable. Nyah!

that makes me wonder if one day we will see nuclear powered passenger planes.

[DarkReaper]

If we grow immune to radiation then maybe. Otherwise all the lawyers would rip you a new one, if someone coughs on the plane.

[Heron]

Meh, forgot about that one.

Though they chose the utterly massive B-36. And used a partially-shielded reactor to reduce weight, as well as using direct air cooling instead of a heat exchanger.

So fission-powered FIGHTERS are still unfeasable. Nyah!

That was 1948-1950's technology. Who knows what we will be able to do in the future when something is "Technically Sweet", like, say:

Project Pluto

Edited September 21, 2008 by Heron

[JB0]

That was 1948-1950's technology. Who knows what we will be able to do in the future when something is "Technically Sweet", like, say:

Project Pluto

Ewww, a ramjet!

Seriously, the nature of fission limits how compact you can make it.

You HAVE to have enough fuel to sustain a chain reaction. And you HAVE to have neutron shielding(even if the NB-36 moved a lot of it to the cockpit). Highly-enriched fuel can reduce the fuel mass but it only does so much for you.

All the technology in the world won't change the fundamental nature of the reactions involved.

[ChronoReverse]

Seriously, the nature of fission limits how compact you can make it.

You HAVE to have enough fuel to sustain a chain reaction. And you HAVE to have neutron shielding(even if the NB-36 moved a lot of it to the cockpit). Highly-enriched fuel can reduce the fuel mass but it only does so much for you.

Fundamentally you only need to have a chain reaction. And you definitely don't need a runaway chain reaction.

At normal densities, you'd need to have a certain mass. Compress it and you'd need a whole lot less. Considering a ball of plutonium smaller than a soccer ball is enough for a runaway reaction (usually results in a "mess"), there's no physical reason why a fission reactor can't be made the size of a Smart Car eventually. Especially if we add in Overtechnology into the mix.

[Morpheus]

Fundamentally you only need to have a chain reaction. And you definitely don't need a runaway chain reaction.

At normal densities, you'd need to have a certain mass. Compress it and you'd need a whole lot less. Considering a ball of plutonium smaller than a soccer ball is enough for a runaway reaction (usually results in a "mess"), there's no physical reason why a fission reactor can't be made the size of a Smart Car eventually. Especially if we add in Overtechnology into the mix.

Besides that, you need materials which could withstand the temperature produced by the nuclear reaction (unless its a cold fission).

[JB0]

Fundamentally you only need to have a chain reaction. And you definitely don't need a runaway chain reaction.

At normal densities, you'd need to have a certain mass. Compress it and you'd need a whole lot less. Considering a ball of plutonium smaller than a soccer ball is enough for a runaway reaction (usually results in a "mess"), there's no physical reason why a fission reactor can't be made the size of a Smart Car eventually. Especially if we add in Overtechnology into the mix.

The size of a Smart, maybe. If you discount support hardware, especially.

Now, fitting IN a Smart, that's another story.

Neutron shielding is unavoldable. It is not reducable. You WILL have a metric butt-ton of lead wrapped around the reactor.

And to make a more compact reactor, you need better fuel(ask the Navy why their nuclear submarines use a more highly-enriched grade of fuel).

A runaway chain reaction ONLY happens if there are no controls.

Though consider: the closer you pack the fuel, the less room you have for control rods, mediators, and coolant. The more you enrich the fuel, the hotter it runs.

Restricting coolant also increases the difficulty of harvesting the heat.

Sure you could build fuel rods of solid U-235 or Pu-239, but it'd be very expensive to fuel, and just plain dangerous on top of that. Not to mention that the government likes to keep weapons-grade nuclear materials under lock and key.

Simply put, microfission isn't a believable technology.

Technology changes, but physics doesn't.

Besides that, you need materials which could withstand the temperature produced by the nuclear reaction (unless its a cold fission).

There's no such thing as cold fission. It's a complete impossibility.

And you need neutron shielding too. Which is a pain in the ass.

Edited September 22, 2008 by JB0

[ChronoReverse]

You seriously need to separate Feasible Within Physics, Feasible Financially, and Feasible With Overtechnology.

I was talking Feasible Within Physics.

Neutron shielding is unavoldable. It is not reducable. You WILL have a metric butt-ton of lead wrapped around the reactor.

And neutron flux is much reduced when you have a much smaller pellet of pure fuel.

Not to mention that lead is a poor neutron shield. You want something with hydrogen like water or plastics.

And to make a more compact reactor, you need better fuel(ask the Navy why their nuclear submarines use a more highly-enriched grade of fuel).

Which is still pointless since I've just postulated the use of near pure fuel.

Though consider: the closer you pack the fuel, the less room you have for control rods, mediators, and coolant. The more you enrich the fuel, the hotter it runs.

You can also use a lot less fuel. Using pure fuel coupled with solid compression (something difficult to do but not beyond physics) along with a manner of neutron flux control that requires less space like shaping and space separation and it's a lot less unfeasible.

Restricting coolant also increases the difficulty of harvesting the heat.

Aren't we using this as a jet engine power source? There's the coolant. The rest is just engineering it such that it doesn't overheat within a certain amount of time.

Sure you could build fuel rods of solid U-235 or Pu-239, but it'd be very expensive to fuel, and just plain dangerous on top of that. Not to mention that the government likes to keep weapons-grade nuclear materials under lock and key.

This isn't about how financially feasible it is. This is about how it's possible within the bounds of physics.

Your thinking is also way too constrained as evidenced by your continued use of "fuel rods" when that might not even be applicable.

Simply put, microfission isn't a believable technology.

Technology changes, but physics doesn't.

And now you're going back to physics?

Ultimately a small fission reactor isn't so much physically impossible but rather extremely difficult (understatement) to engineer and fantastically expensive (also an understatement). But that's entirely different from "breaking the laws of physics".

Edited September 22, 2008 by ChronoReverse

[sucker4meltrans]

valks flying in all modes are still more possible/plausible looking then any flying mecha from Gundam. just look at the gundam exiga from gundam emo, err i mean gundam 00.