VF-1 Exhaust Internals

[BEAST]

"SLITS"

In the SDFM TV series (and maybe even a few scenes of DYRL?), a series of narrow horizontal orifices can be seen inside the exhausts of Valks, ahead of the vectored thrust nozzles/feet. There usually appear to be 5 such narrow openings, but sometimes as many as 7 depending on the animation & episode. They appear to expand outwards with the feet halves, like a peacock's tail feathers.

"SLOTS"

However, in the Yammy 1/48 toys, conventional round turbines or afterburner rings can be seen inside the exhausts, without the horizontal slits.

So what was the purpose of such horizontal slits in the exhaust in the first place? Were they akin to the "platypus" exhaust of the F-117? Perhaps some sort of hardware familiar to nuclear devices? Or was it something else?

And was there any particular reason for a transition to the more conventional-looking exposed round turbines in the Yammy toys (other than the relative simplicity of the mold)?

It sure seems like sticking all that hardware up the engines' rear-ends would interfere with thrust.

[Nied]

I always figured the slits were there to difuse the exhaust somewhat to prevent ground erosion. Without them a VF-1 would make a great tool for digging holes for telephone poles.

[Skull-1]

"SLITS"

In the SDFM TV series (and maybe even a few scenes of DYRL?), a series of narrow horizontal orifices can be seen inside the exhausts of Valks, ahead of the vectored thrust nozzles/feet. There usually appear to be 5 such narrow openings, but sometimes as many as 7 depending on the animation & episode. They appear to expand outwards with the feet halves, like a peacock's tail feathers.

"SLOTS"

However, in the Yammy 1/48 toys, conventional round turbines or afterburner rings can be seen inside the exhausts, without the horizontal slits.

So what was the purpose of such horizontal slits in the exhaust in the first place? Were they akin to the "platypus" exhaust of the F-117? Perhaps some sort of hardware familiar to nuclear devices? Or was it something else?

And was there any particular reason for a transition to the more conventional-looking exposed round turbines in the Yammy toys (other than the relative simplicity of the mold)?

It sure seems like sticking all that hardware up the engines' rear-ends would interfere with thrust.

The Slits probably serve multiple purposes...

1) Diffusion of exhaust -- reduces radar, noise, and thermal signature.

2) Vectoring - Allows for rapid changes in nozzle output for assymetric thrust maneuvers.

I had a few others but my mind went numb.

[ghostryder]

So why do Yammie VF-1's have round turbines? I remember those rectangular exhaust ports in the series, and yet SK was supposed to have approved the 1/48. Which is lineart correct?\

Not that it means anything, but all the Toynamis have rectangular ports.

[eugimon]

So why do Yammie VF-1's have round turbines? I remember those rectangular exhaust ports in the series, and yet SK was supposed to have approved the 1/48. Which is lineart correct?\

Not that it means anything, but all the Toynamis have rectangular ports.

good point. I wonder if the turbine was a compromise made on the toy.

[Dante74]

Can we get some pics please?

[azrael]

And was there any particular reason for a transition to the more conventional-looking exposed round turbines in the Yammy toys (other than the relative simplicity of the mold)?

Yes. SDFM = Slits. DYRL = no slits. Yammies are based off the DYRL designs. Very simple.

[ghostryder]

Is this official TV lineart? It shows turbines.

[Skull-1]

I recall Hikaru's Gerwalk retro from the animation. I it had slits but they were coupled to the foot walls (in some shots). Thus they could potentially lie flat.

That may be what we see here.

Then again, perhaps early Block Valks had slits and later Block deleted them (they are probably a MX nightmare).

Edited January 4, 2007 by Skull-1

[Nied]

Yes. SDFM = Slits. DYRL = no slits. Yammies are based off the DYRL designs. Very simple.

Actually you can see the slits clearly in several scenes in DYRL too. I've loaned my copy of DYRL to a freind so I can't pull a screen grab, but if you freeze frame the shot of Hikaru swiching to GERWALK at the begining of the movie (right after Skull team fires thier first salvo of misiles) you can see them pretty clearly. I'm not sure why most 3-d representations now feature the afturburner rings (which is just damn odd since the VF-1 doesn't have afterburners).

Is this official TV lineart? It shows turbines.

IIRC that's from TIAS Macross Plus, and might be the first time we see the slits replaced with afterburner cans.

[Skull-1]

Actually you can see the slits clearly in several scenes in DYRL too. I've loaned my copy of DYRL to a freind so I can't pull a screen grab, but if you freeze frame the shot of Hikaru swiching to GERWALK at the begining of the movie (right after Skull team fires thier first salvo of misiles) you can see them pretty clearly. I'm not sure why most 3-d representations now feature the afturburner rings (which is just damn odd since the VF-1 doesn't have afterburners).IIRC that's from TIAS Macross Plus, and might be the first time we see the slits replaced with afterburner cans.

How does it *NOT* have burners?

[David Hingtgen]

It has "overboost". How do you expect a conventional afterburner to work in space? Sure you may get a big blue glow, but it's not "raw kerosene-based fuel being burned with oxygen". The visual effect/comparison is obvious, but IMHO it can't actually be an afterburner.

[Nied]

What David said. Because thermonuclear turbines work by heating reaction mass (air in the atmosphere or something else in space) instead of burning fuel, just dumping reaction mass into the exhaust stream afterburner style would create less thrust than simply dumping more fuel into the primary reaction chamber.

Edited January 4, 2007 by Nied

[Skull-1]

It has "overboost". How do you expect a conventional afterburner to work in space? Sure you may get a big blue glow, but it's not "raw kerosene-based fuel being burned with oxygen". The visual effect/comparison is obvious, but IMHO it can't actually be an afterburner.

An afterburner does what an afterburner does.

In this case, a fusion powered engine dumps plasma into the exhaust coupled with (potentially combustible) reaction mass to increase thrust.

Afterburner.

A.k.a. "reheat."

Same principle.

Same process.

Potentially different materials used.

It's still a burner.

Blue flame is simply hotter than orange.

Edited January 4, 2007 by Skull-1

[azrael]

Actually you can see the slits clearly in several scenes in DYRL too.

They showed the slits there? Oh well, it's been years since I've seen DYRL.

[Skull-1]

What David said. Because thermonuclear turbines work by heating reaction mass (air in the atmosphere or something else in space) instead of burning fuel, just dumping reaction mass into the exhaust stream afterburner style would create less thrust than simply dumping more fuel into the primary reaction chamber.

Depends on what kind of RM you dump into the system.

If it is a propellant then it will increase thrust.

Dumping fuel into the primary reaction chamber may not do anything other than overtemp the turbine.

This airplane appears to have three different fan sections. I am sure that dumping combustible RM into the rear stage(s) will increase thrust.

[Nied]

Yes but like I said, dumping extra reaction mass into the exhaust would create less thrust than dumping that same reaction mass into the the normal intermix chamer. Thermonuclear turbines work by using a fusion reaction to superheat a reaction mass instead of combusting flamables, dumping fusion plasma into the exhaust stream wouldn't heat the reaction mass as much as keeping it in the intermix stage, and dumping raw reaction mass into the exhaust would actually cool it giving you less thrust. I'm at work at the moment but there is line art of the Valkyrie's throttle quadrant clearly showing that it has no Afterburner detents only overboost (up to IIRC 130%).

[Skull-1]

Yes but like I said, dumping extra reaction mass into the exhaust would create less thrust than dumping that same reaction mass into the the normal intermix chamer. Thermonuclear turbines work by using a fusion reaction to superheat a reaction mass instead of combusting flamables, dumping fusion plasma into the exhaust stream wouldn't heat the reaction mass as much as keeping it in the intermix stage, and dumping raw reaction mass into the exhaust would actually cool it giving you less thrust. I'm at work at the moment but there is line art of the Valkyrie's throttle quadrant clearly showing that it has no Afterburner detents only overboost (up to IIRC 130%).

I know what you are trying to say. What I am saying is that metal (or whatever the reactor is composed of) can only take so much. I assure you that the inside of an intermix stage in a fusion turbine is going to be hot enough to reduce everything in there to slag. Your only hope in the atmosphere is to then superheat bypass air downstream of that intermix turbine. You can do that through numerous means.

You call it overboost I call it an afterburner the Brits call it a reheat. The principle is the same. The air is heated just prior to exiting the tailfeathers using fuel (or fusion, raw plasma, whatever anime magic you want to name).

It may not be a true "afterburner" if a non-combustible heating element is used, but it is an "AFTERHEATER."

And yes I recall the throttle quadrant.

(But pilots speak of what they know and I can assure you they will still say "burner" even if it is truly a "booster.")

Edited January 4, 2007 by Skull-1

[ghostryder]

The first fight seen in DYRL clearly shows the slits. I guess SK overslept the day Yamato was supposed to show him the protoype 1/48 feet.

After reading all this, I tend to agree that reaction engines would not need afterburners or burner rings. I mean, the reaction occurs in one chamber, and then is expelled out of the exhaust. Assuming that OT can deal with the heat of a fusion reaction, why would there be a need for two stages of reaction, or bypass air/plasma? Even if there was bypass air/plasma, the only way to create additonal thust in space would be another fusion stage with addtional reaction mass added.

[Skull-1]

The first fight seen in DYRL clearly shows the slits. I guess SK overslept the day Yamato was supposed to show him the protoype 1/48 feet.

After reading all this, I tend to agree that reaction engines would not need afterburners or burner rings. I mean, the reaction occurs in one chamber, and then is expelled out of the exhaust. Assuming that OT can deal with the heat of a fusion reaction, why would there be a need for two stages of reaction, or bypass air/plasma? Even if there was bypass air/plasma, the only way to create additonal thust in space would be another fusion stage with addtional reaction mass added.

Bypass air is needed because a fan is more efficient at lower altitudes than a pure jet would be. You have a faster reaction time to acceleration with a fan as opposed to a pure jet. The fan helps propel the aircraft. An "afterheater" would simply add velocity to the bypass air as needed to increase thrust.

As for additional thrust in space, again, propellant can increase thrust. The mass of the propellant or RM expended will affect thrust. Just as heavier jet fuels provide more thrust per volume so too does RM.

IMHO an afterburner ("afterheater") on a Valkyrie is probably just that--an additional fusion stage of one kind or another or an area to vent additional RM. Regardless, heating the bypass air will not decrease thrust by any means.

This engine appears to have three "N1" fan sections, two "N1" fan sections with a single "N2", or two "N2" fan sections with a single "N1". There are three large fans there from my viewing of the line art.

Edited January 4, 2007 by Skull-1

[David Hingtgen]

I'm saying that we have little to no evidence at all how "overboost" works. Perhaps it's an entirely different system somewhere in the engine nacelle, akin to JATO or something. Maybe it's super-heated liquid quartz sprayed onto the stator vanes, which reacts with some exotic OT metal to create glowing blue thrust...

My point is, it shouldn't be called an afterburner because we don't have the slightest clue how it works. Since it's obviously based on a real-life afterburner, it was *probably* intended to work roughly the same. But we don't have any indication that it is in fact at all similar, AFAIK.

If it's to be called an afterburner, then we need evidence that:

1. It occurs in the exhaust, after any of the engine's own stages. If it's in the turbine/reaction chamber, it's not "after", it's "core".

2. It involves heat/burning. Maybe the blue glow is electical in nature, or visible magnetic field effects. It could actually be ice-cold for all we know. The only thing we know is that it's blueish----maybe it's actually a micro-warp-engine, stolen from Starfleet.

[Skull-1]

I doubt magnets would make a roaring sound.

We certainly hear thrust noise akin to *combustion* when (among other instances) Hikaru tries to stop his VF-1D from plowing into a Zentraedi Soldier around Episode Three.

Afterheater would be my term for it.....

But no pilot is going to call it an Afterheater. He'll just call it a burner and be done with it.

[Beltane70]

Is this official TV lineart? It shows turbines.

IIRC that's from TIAS Macross Plus, and might be the first time we see the slits replaced with afterburner cans., and might be the first time we see the slits replaced with afterburner cans.

It was reprinted in TIAS Macross Plus. The lineart also appears in Macross Perfect Memory on page 151.

Perfect Memory also shows the throttle controls for the VF-1 having an afterburner setting as well as the overboost setting. The VF-1's throttle settings according to Perfect Memory text and lineart are as follows:

Idle 1~2%

Cruise 50%

Military 75%

Max 100%

Afterburner 120%

Overboost 200%

Reverse

TIAS Macross Plus also shows the lineart for the throttle controls on page 61.

[Skull-1]

I thought it had a "Burner" setting.

Good job.

[anime52k8]

And was there any particular reason for a transition to the more conventional-looking exposed round turbines in the Yammy toys (other than the relative simplicity of the mold)?

I think the simulated burner cans on the 1/48 is just an example of Yamato being lazy. Basically all they put was a ring and some strait spokes stamped into the feet, which is a lot easier than trying to mold the exhaust slits in the show.

(Interestingly this is the only area that the MPC Valks are more accurate)

[Nied]

I know what you are trying to say. What I am saying is that metal (or whatever the reactor is composed of) can only take so much. I assure you that the inside of an intermix stage in a fusion turbine is going to be hot enough to reduce everything in there to slag. Your only hope in the atmosphere is to then superheat bypass air downstream of that intermix turbine. You can do that through numerous means.

Actually running more reaction mass through the engine would cool it not heat it. Remember while similar a thurmonuclear turbine (at leat as it's explained in Macross) is not a jet engine. Heat from the fusion reacion is transfered to the reaction mass instead of igniting a fuel air mixture, the more heat transfered to the mass shooting out the back, the less there is in the reactor, it's basic thermodynamics. If anything the danger would be in cooling the reactor down to a point where it can no longer sustain a fusion reaction.

Dumping anything into the exhaust afterburner style would be extrememly ineffeicaent. The exhaust from the core is rapidly expanding and thus cooling (again thermodynamics) so dumping reaction mass into the exhaust stream would if anything it help cool it further thus reducing its energy. Bypas air is reletively diffuse (and judging from the cut aways of the engine there isn't very much of it) compared to the higly compressed air moving through the core so dumping plasma into it wouldn't give you more than a miniscule kick.

You call it overboost I call it an afterburner the Brits call it a reheat. The principle is the same. The air is heated just prior to exiting the tailfeathers using fuel (or fusion, raw plasma, whatever anime magic you want to name).

It may not be a true "afterburner" if a non-combustible heating element is used, but it is an "AFTERHEATER."

And yes I recall the throttle quadrant.

(But pilots speak of what they know and I can assure you they will still say "burner" even if it is truly a "booster.")

Actually overboost is distinct from afterburner and exists in modern jet engines (I've only heard of it in military fighters though). Overboost just consits of running an engine past 100% for short periods of time with a consequently lower TBO. IIRC the Su-33 has 133% overboost setting that is only to be used in conjuncton with afterburners during carrier takeoffs.

IMHO an afterburner ("afterheater") on a Valkyrie is probably just that--an additional fusion stage of one kind or another or an area to vent additional RM. Regardless, heating the bypass air will not decrease thrust by any means.

This engine appears to have three "N1" fan sections, two "N1" fan sections with a single "N2", or two "N2" fan sections with a single "N1". There are three large fans there from my viewing of the line art.

There's only one fusion toroid visible in the cutaways of the engine, and it's impossible to get a slef sustaining fusion reaction to start in the aft end of the engine is close to impossible. And if it were I'd hate to be anywhere within 100 miles of the rear end of a Valkyrie when it lit off as it would be spweing gamma readiation.

I doubt magnets would make a roaring sound.

We certainly hear thrust noise akin to *combustion* when (among other instances) Hikaru tries to stop his VF-1D from plowing into a Zentraedi Soldier around Episode Three.

The 'combustion' sound of a modern jet engine is merely the result of the high speed superheated air from the engine interacting with the slower cooler air outside. It really wouldn't matter if the heat is provided by a fusion reactor and the high speed from a magneto hydrodynamic element youd still hear pretty much the same roar.

[David Hingtgen]

The F-15 has a "beyond normal limits" button, but it's so piddly it's not really worth mentioning--thought pilots sure like to brag about using it. It's like 2% more N2 and a 4% higher EGT limit. Of course, F-15 normal engine trim is like 98% of rated thrust (a little less thrust gives a LOT more reliability and engine life), so it's not really "beyond", but more like "back up to full spec".

Airliners (except RR-powered) have take-off thrust set at over 100%, with a 5 minute limit (10 in an emergency), usually in the 103-107% range. Skull-1 could certainly expand on that.

The MD-11 is the only one I can think of that has something really notable: If you push the throttles beyond their normal stop, and break past the stop, they'll go up to 117% rated thrust through sheer increased fuel flow/temps. Good for about 20-30 secs before they'll overheat. Never heard of it being used, but it's there.

As for noise: jet engines have 2 main, distinct sounds: The "whine" of the machinery, which is part fan noise but mostly turbine noise (though a "buzzsaw" noise usually means the fan is louder than the turbine--exclusive to high-bypass AFAIK), and the "roar" noise which is literally jet noise---rapidly moving air. Thunder is the ultimate expression of jet noise---super-heated air moving super-fast. As opposed to "quite hot" air moving "quite" fast. Lightning gets the air hot and moving far better than any engine.

Best way to quiet an engine is to slow down the air---and colder air has less energy. But that'll decrease thrust, so you need more air. 777 engines are the best example--they are QUIET, despite being the most powerful jets of all. Sheer quantity of air, moving quite slowly by jet standards.

[Skull-1]

Actually running more reaction mass through the engine would cool it not heat it.

You aren't running RM literally "through" the engine though in the sense of it mixing together. The plasma of the turbine is kept apart from the RM itself. Othewise I think you'd radiate the atmosphere and that would be unacceptable.

The transference of heat from the reactor to the RM (air / water whichever) is what produces your thrust.

You have two options...

1) Heat a smaller volume of air to a higher total temp to increase the velocity of the exhuast gas to a very high level.

2) Heat a larger volume of air to a lower (but hotter) total temp and increase the velocity of the exhasut gas to a (relatively) moderate speed.

If you choose to do the former you are going to accelerate very slowly.

The Valkyrie flits about the sky like a mosquito. I don't see how it does so without some chemical / combustible / RM Afterburner to heat the bypass air as well as to provide a "rocket" effect.

Edited January 4, 2007 by Skull-1

[Skull-1]

Airliners (except RR-powered) have take-off thrust set at over 100%, with a 5 minute limit (10 in an emergency), usually in the 103-107% range. Skull-1 could certainly expand on that.

Not by much.

On the Embraer Legacy for example, we have three takeoff thrust modes that equate to 90%, 100%, and 110% of normal thrust. We use the minimum necessary for our takeoff weight (if we can't get off the ground at 90% we go to 100%, if 100% won't work we go to 110%). Any engine failure is handled through the FADEC by an Automatic Takeoff Thrust Control System (ATTCS) and that bumps you to the next thrust setting on the operating engine.

Condition: Mode = Thrust

Both Engines Operating: ALT-T/O = 90% - Engine Failure: ALT T/O-1 = 100%

Both Engines Operating: T/O = 100% - Engine Failure: T/O-1 = 110%

Both Engines Operating: E T/O = 110% - Engine Failure: E T/O RSV = 117% (8,810 lbs. st.)

Best way to quiet an engine is to slow down the air---and colder air has less energy. But that'll decrease thrust, so you need more air. 777 engines are the best example--they are QUIET, despite being the most powerful jets of all. Sheer quantity of air, moving quite slowly by jet standards.

Which won't work too well on a Mach 3+ Valkyrie I'm betting.

Edited January 4, 2007 by Skull-1

[anime52k8]

Can I just ask because I'm totally confused at this point...

How are these "thermonuclear turbines" supposed to work? Are they like real nuclear jet engine which just passes air over a reactor core (or heat transfer medium) to super heat it or is it something completely different. And what is Reaction mass, is it supposed to be like compressed gas stored on board for space use only or is it an actual fuel that gets burned. I really have no Idea what's going on anymore could someone explain this.

Edited January 4, 2007 by anime52k8

[JB0]

Can I just ask because I'm totally confused at this point...

How are these "thermonuclear turbines" supposed to work? Are they like real nuclear jet engine which just passes air over a reactor core (or heat transfer medium) to super heat it or is it something completely different.

That's the likely operational concept.

Essentially, the "fire" in a standard jet engine has been replaced with a heat exchanger tied to a (very) small star.

And what is Reaction mass, is it supposed to be like compressed gas stored on board for space use only or is it an actual fuel that gets burned. I really have no Idea what's going on anymore could someone explain this.

Reaction mass = whatever you throw out the back to make your ship move forward.

In an atmosphere, this is the air you suck into your jet.

In space, it can be something you burn, something you just spray out, something you mix for a non-flammable expansion, or even something you throw about with your hands(the metal tanks Hikaru uses when he's "fishing" are reaction mass, albeit a very simple one.

The term's usually only applied to space travel as far as I know, since reaction mass in an airplane is pretty much by definition the air around it.

The Valk's hybrid nature makes reaction mass come up in a field where it normally doesn't.

I admit to having very little understanding of jet propulsion, but I don't really see how an afterburner is going to work on a Valk. Certainly not in space, since it seems to me that they won't work worth crap without the confining pressure of the atmosphere holding the exhaust together while your afterburner fuel burns(and as previously noted, injecting cold reaction mass into your exhaust stream will be nothing but detrimental).

I always liked the argument that the afterburner setting was an anachronism included mainly for the comfort of pilots from the unification wars. It's simple and logical.

Edited January 4, 2007 by JB0

[eugimon]

the only way I see "afterburners" working in space, is that the standard top operational speed of the valk is constrained by what the engine itself can safely handle. Afterburn pushes the engine into the red zone, giving more acceleration but stressing the engines.

[anime52k8]

thanks JBO that makes much more sence.

I denfenatly don't see how you could actualy have an afterburner on an engine that uses nuclear power since your not realy burning anything.

[Mr March]

Is this official TV lineart? It shows turbines.

That is official line art. It is taken from the old 1983 book Macross Perfect Memory and is drawn by Kawamori himself.

[Mr March]

IIRC that's from TIAS Macross Plus, and might be the first time we see the slits replaced with afterburner cans.

Nope, it's from MPM, see above.