USAF/US NAVY 6th Generation Fighter Programs - F/A-XX, F-X, NGAD, PCA, ASFS news

[Sundog]

Venting it quickly means ruining IR stealth, so accumulators storing the energy and trickling it out later have been considered, but N-G has another idea that they're not talking about...

Dumping the heat into the fuel right before it's burned, maybe?

 

[ubiquitous08]

lol preheating fuel for superior cruise efficiency....

 

[Moose]

Venting it quickly means ruining IR stealth, so accumulators storing the energy and trickling it out later have been considered, but N-G has another idea that they're not talking about...

Dumping the heat into the fuel right before it's burned, maybe?

Heat sinks in fuel tanks for the radar and CPUs are already a thing, I don't know at what point the laser outs out tok much heat for that to be practical. I wonder if the Reaction Engines super duper heat exchanger technology can scale to the problem.

 

[AeroFranz]

Not that there's another obvious solution, but dumping heat in fuel tanks has its obvious limitations. You are relying on always having enough fuel in the tanks to absorb the heat. What if your airplane has been sitting in the desert sun for several hours right before the mission? pre-chilling the fuel sounds impractical, at least operationally.

 

[Sundog]

Not that there's another obvious solution, but dumping heat in fuel tanks has its obvious limitations. You are relying on always having enough fuel in the tanks to absorb the heat. What if your airplane has been sitting in the desert sun for several hours right before the mission? pre-chilling the fuel sounds impractical, at least operationally.

Maybe some sort of heat exchanger that turns the heat into electricity to recharge capacitors used for the laser? Of course, that all adds weight and volume, but I'm intrigued by their statement and what they came up with to solve the problem.

 

[GTX]

I wonder if one could integrate the heat exchanger with the propulsion system? Dump the heat into the airflow as a companion to the combustion section - when dumping such heat, the fuel burn cut back accordingly thus actually saving fuel whilst maintaining performance. It would take some serious engineering and maths to do but maybe...

 

[flateric]

...

 

[bobbymike]

Article in Flight Global about Northrop Grumman's NGAD programme, specifically about laser weapons and thermal management. The highlight is a fairly decent, clear image of the current concept.

https://www.flightglobal.com/news/articles/northrop-beating-heat-leads-sixth-generation-fighte-420006/

Lasers have only about a third efficiency meaning that for every MW or directed energy, there's 2MW of heat to deal with. Venting it quickly means ruining IR stealth, so accumulators storing the energy and trickling it out later have been considered, but N-G has another idea that they're not talking about...

Single engine ADVENT type? Has there been other 'iterations' of 6th Gen showing a single engine?

 

[XP67_Moonbat]

http://foxtrotalpha.jalopnik.com/this-is-northrop-grummans-idea-of-a-sixth-generation-fi-1747680825

 

[flateric]

Article in Flight Global about Northrop Grumman's NGAD programme, specifically about laser weapons and thermal management. The highlight is a fairly decent, clear image of the current concept.

https://www.flightglobal.com/news/articles/northrop-beating-heat-leads-sixth-generation-fighte-420006/

Lasers have only about a third efficiency meaning that for every MW or directed energy, there's 2MW of heat to deal with. Venting it quickly means ruining IR stealth, so accumulators storing the energy and trickling it out later have been considered, but N-G has another idea that they're not talking about...

Single engine ADVENT type? Has there been other 'iterations' of 6th Gen showing a single engine?

This one is two-engined concept, first surfaced as early as 2012.

 

[jsport]

Article in Flight Global about Northrop Grumman's NGAD programme, specifically about laser weapons and thermal management. The highlight is a fairly decent, clear image of the current concept.

https://www.flightglobal.com/news/articles/northrop-beating-heat-leads-sixth-generation-fighte-420006/

Lasers have only about a third efficiency meaning that for every MW or directed energy, there's 2MW of heat to deal with. Venting it quickly means ruining IR stealth, so accumulators storing the energy and trickling it out later have been considered, but N-G has another idea that they're not talking about...

Single engine ADVENT type? Has there been other 'iterations' of 6th Gen showing a single engine?

This one is two-engined concept, first surfaced as early as 2012.

Go Blended Wing Body.

 

[Sundog]

GE's Adaptive Engine apparently uses the third stream (2nd bypass?) to absorb the heat generated by the systems onboard a modern combat aircraft. Just an FYI. Although, this isn't apparently what Northrop is using, since it get's dumped overboard in the exhaust. I wonder if this new technique is something they're using on their LRSB?

 

[marauder2048]

Not that there's another obvious solution, but dumping heat in fuel tanks has its obvious limitations. You are relying on always having enough fuel in the tanks to absorb the heat. What if your airplane has been sitting in the desert sun for several hours right before the mission? pre-chilling the fuel sounds impractical, at least operationally.

Maybe some sort of heat exchanger that turns the heat into electricity to recharge capacitors used for the laser? Of course, that all adds weight and volume, but I'm intrigued by their statement and what they came up with to solve the problem.

The cooling mechanism could be hidden in plain sight: optical refrigeration AKA laser cooling. There are heat-pumped lasers as you mention but I think that relies on the heat capacitor solution NG rejected.

 

[flateric]

http://m.aviationweek.com/defense/northrop-grumman-studies-technologies-f-22-fa-18-replacement

 

[Ian33]

I recall seeing here on Secret Projects an engine that had the exhaust along the entire rear of the wing. Northrop IIRC for a bomber or transport.

Why not do the same for laser cooling? Air diverted, heated, then cooled by another stream before ducted out through porous flaps trailing edges.

 

[marauder2048]

Animated Sequence from a scenario described in CSBA's "Trends in Air-to-Air Combat: Implications For Future Air Superiority"

https://youtu.be/N3VUK7h6x8A

 

[pedrospe]

Thanks everyone for these great pictures,finally, we already have images for the fa-xx program,from Boeing and Northrop Grumman,now the only one missing is an image from lockheed martin,which only showed it's concept for the air force f-x program...

best regards

Pedro

 

[sferrin]

You do realize these are all notional and most likely bare no resemblance to any actual design right?

 

[DrRansom]

I don't know, the aerodynamic and systems restrictions kind of place a limit on the fighter.

If the USN / USAF wants a long range fighter with a high-powered internal laser and all-aspect stealth, then that plane will start looking like the images. Unless there's a breakthrough in aerodynamics in the next 5 years.

 

[sferrin]

I don't know, the aerodynamic and systems restrictions kind of place a limit on the fighter.

If the USN / USAF wants a long range fighter with a high-powered internal laser and all-aspect stealth, then that plane will start looking like the images. Unless there's a breakthrough in aerodynamics in the next 5 years.

Sure. That would explain why the YF-23 and F-22 look the same. There are a lot of ways to skin the cat. No way is any company going to tip it's hand at this point.

 

[Steve Pace]

If the YF-23 and F-22 look alike then that explains why the XB-70 and SR-71 look so much alike. NOT! -SP

 

[DrRansom]

Sure. That would explain why the YF-23 and F-22 look the same. There are a lot of ways to skin the cat. No way is any company going to tip it's hand at this point.

I'm not quite sure if that experience reinforces your position. The difference between the YF-23 and F-22 reflected a different opinion about what the USAF wanted at that point in time, YF-23 was designed towards high speed high altitude high stealth fighters, F-22 was more traditional with high maneuverability. In fact, this difference in design philosophies ensures that the 'What If' discussion will continue until the F - X program.

However, a future F-X program which has a tighter design space, and going for long range performance will tighten that design space considerably, should produce a closer alignment of aircraft design.

But, I concede that firms will not be willing to show designs which contain completely unique aerodynamic features. That has to wait for the competition.

 

[sferrin]

Sure. That would explain why the YF-23 and F-22 look the same. There are a lot of ways to skin the cat. No way is any company going to tip it's hand at this point.

I'm not quite sure if that experience reinforces your position. The difference between the YF-23 and F-22 reflected a different opinion about what the USAF wanted at that point in time, YF-23 was designed towards high speed high altitude high stealth fighters, F-22 was more traditional with high maneuverability. In fact, this difference in design philosophies ensures that the 'What If' discussion will continue until the F - X program.

They both received the same set of requirements. They both met the same set of requirements. And NG could have just as easily added TVC to their aircraft if they'd felt it was worth it. Radically different designs for the same requirement. (Neither of them looking anything like the ATF art floating around at the time either I might add.) Same thing with the X-32/X-35. Same thing with the YF-16/YF-17.

 

[DrRansom]

On the topic of thermal requirements:

Optimal Cruise Altitude for Aircraft Thermal Management
David B. Doman
Journal of Guidance, Control, and Dynamics, 2015, Vol.38: 2084-2095, 10.2514/1.G000845

 

[bring_it_on]

...

 

[flateric]

http://breakingdefense.com/2015/12/northrop-unveils-sixth-gen-fighter-concept/

 

[F-14D]

I don't know, the aerodynamic and systems restrictions kind of place a limit on the fighter.

If the USN / USAF wants a long range fighter with a high-powered internal laser and all-aspect stealth, then that plane will start looking like the images. Unless there's a breakthrough in aerodynamics in the next 5 years.

Sure. That would explain why the YF-23 and F-22 look the same. There are a lot of ways to skin the cat. No way is any company going to tip it's hand at this point.

Do I detect a note of sarcasm that some may have missed?

 

[marauder2048]

I don't know, the aerodynamic and systems restrictions kind of place a limit on the fighter.

If the USN / USAF wants a long range fighter with a high-powered internal laser and all-aspect stealth, then that plane will start looking like the images. Unless there's a breakthrough in aerodynamics in the next 5 years.

Sure. That would explain why the YF-23 and F-22 look the same. There are a lot of ways to skin the cat. No way is any company going to tip it's hand at this point.

Do I detect a note of sarcasm that some may have missed?

I would think you would bump into Elevator/EMALS/AAG constraints long before you start rubbing up against the ragged edge of aero or systems.

 

[donnage99]

I'm not quite sure if that experience reinforces your position. The difference between the YF-23 and F-22 reflected a different opinion about what the USAF wanted at that point in time, YF-23 was designed towards high speed high altitude high stealth fighters, F-22 was more traditional with high maneuverability. In fact, this difference in design philosophies ensures that the 'What If' discussion will continue until the F - X program.

Actually, their visual difference has more to do with their stealth techniques. Northrop choose to start out with a flat surface parallel to the horizontal plane, then they contuour that surface to add in appropriate internal components. The point is not to have any abrupt break on the surface, thus why you can see the contours on that bird being very dramatic. Lockheed took almost the opposite approach - their design is basically a combination of multiple flat surfaces with as minimal contours as possible.

 

[marauder2048]

I'm not quite sure if that experience reinforces your position. The difference between the YF-23 and F-22 reflected a different opinion about what the USAF wanted at that point in time, YF-23 was designed towards high speed high altitude high stealth fighters, F-22 was more traditional with high maneuverability. In fact, this difference in design philosophies ensures that the 'What If' discussion will continue until the F - X program.

Actually, their visual difference has more to do with their stealth techniques. Northrop choose to start out with a flat surface parallel to the horizontal plane, then they contuour that surface to add in appropriate internal components. The point is not to have any abrupt break on the surface, thus why you can see the contours on that bird being very dramatic. Lockheed took almost the opposite approach - their design is basically a combination of multiple flat surfaces with as minimal contours as possible.

But I think the point being made is: would visual inspection alone tell you that the YF-23 met (or exceeded) the ATF subsonic and supersonic maneuverability requirements through the use of the some of the largest, highest rate, highest hinge moment generating control surfaces ever attached to a fighter?

 

[flateric]

http://nationalinterest.org/blog/the-buzz/exposed-first-look-northrops-sixth-gen-stealth-fighters-14613

in hi-res

 

[DrRansom]

donnage - thanks for the explanation.

It looks like Northrop's publicity campaign has succeeded, their fighter concept has reached the Daily Mail:
http://www.dailymail.co.uk/sciencetech/article-3359934/The-stealth-superwing-generation-Air-Dominance-fighter-jet-built-laser-weapons-revealed.html

 

[sferrin]

I don't know, the aerodynamic and systems restrictions kind of place a limit on the fighter.

If the USN / USAF wants a long range fighter with a high-powered internal laser and all-aspect stealth, then that plane will start looking like the images. Unless there's a breakthrough in aerodynamics in the next 5 years.

Sure. That would explain why the YF-23 and F-22 look the same. There are a lot of ways to skin the cat. No way is any company going to tip it's hand at this point.

Do I detect a note of sarcasm that some may have missed?

Definitely. I doubt Northrops concept would end up looking anything at all like the recent artwork would imply.

 

[bring_it_on]

Sorry we couldn't show you an actual design of our new trainer that we plan on flying in about a month but here's an accurate description of our F-X offering for the 2030's

 

[bobbymike]

https://www.flightglobal.com/news/articles/boeing-phantom-works-keeping-t-x-and-f-x-plans-under-420044/

 

[LowObservable]

It's pure PR that both are playing so coy, since I really, really doubt that there is going to be any ZOMG factor like we saw with YF-23 or F-117.

 

[sublight_]

....I really, really doubt that there is going to be any ZOMG factor like we saw with YF-23 or F-117.

There are so many "Buck Rogers" developments happening right now with meta-materials that ZOMG is definitely still on the table.

 

[sferrin]

....I really, really doubt that there is going to be any ZOMG factor like we saw with YF-23 or F-117.

There are so many "Buck Rogers" developments happening right now with meta-materials that ZOMG is definitely still on the table.

If LM rolled out the design they've had around there would definitely be ZOMG-factor. Same with one of the Boeing designs.

 

[LowObservable]

Oh rats, that was intended to be a comment on the TX thread.

 

[DrRansom]

sferrin - any reason why the Stealth aircraft other than to show the absurdity of images 15 years in advance of the program?

Though, I'd love it if the winning F-X design followed the Switchblade.. Swing wing forward swept, that'd be something else. (Also absurdly unlikely, etc., etc., but who cares?)