Jump to content


Photo

Little Flying Dragons Of China


  • Please log in to reply
323 replies to this topic

#41 Josh

Josh

    Crew

  • Members
  • PipPip
  • 14,102 posts
  • Gender:Male
  • Location:New York City

Posted 20 November 2017 - 1245 PM

60 would be a lot more than I would have thought. I thought the entire H-6 force was rough 120 machines, but it must be much larger unless older variant are being retired as the K comes online. I had heard once before that the production rate was a dozen airframes per year, but I think it must rather higher. I wonder what the total production run will be? I would have thought 100-200 total.


  • 0

#42 JasonJ

JasonJ

    nemui

  • Members
  • PipPip
  • 10,200 posts
  • Gender:Male
  • Location:doko da?!
  • Interests:Sleeping

Posted 21 November 2017 - 1322 PM

It's really hard to guess what total production will be.

 

Anyway, maybe this image is useful, probably J-10B. Can its radar quality or capabilities be speculated with this?

j-10bmaybe.jpg

https://www.facebook...?type=3


  • 0

#43 Josh

Josh

    Crew

  • Members
  • PipPip
  • 14,102 posts
  • Gender:Male
  • Location:New York City

Posted 21 November 2017 - 1415 PM

Looks like an AESA, but I don't think that's particularly news.
  • 0

#44 JasonJ

JasonJ

    nemui

  • Members
  • PipPip
  • 10,200 posts
  • Gender:Male
  • Location:doko da?!
  • Interests:Sleeping

Posted 24 November 2017 - 0353 AM

There's a new version of the H-6 coming out, apparently soon, called the H-6KH. Is said that first flight was in 2014.

Two model images in the spoiler and the usual blurry and top-down teaser view image.

H-6KHo3.jpg

Spoiler

https://baike.baidu....om/item/轰-6KH

http://slide.mil.new..._52803.html#p=6

Chinese text from first link in spoiler

Spoiler


  • 0

#45 Josh

Josh

    Crew

  • Members
  • PipPip
  • 14,102 posts
  • Gender:Male
  • Location:New York City

Posted 25 November 2017 - 1004 AM

It looks like there's a ventral targeting pod and a pair of outboard jammers of some kind. Do any of the articles list the changes to the new model?

I find it fascinating they still are producing new builds of an aerodynamic shape that debuted over half a century ago. Avionics wise, I'm sure its very modern and as cutting edge as they can make it. In terms of the airframe, it inferior to the B-52 or especially the B-1 in pretty much every measurable way.
  • 0

#46 JasonJ

JasonJ

    nemui

  • Members
  • PipPip
  • 10,200 posts
  • Gender:Male
  • Location:doko da?!
  • Interests:Sleeping

Posted 25 November 2017 - 1805 PM

If they keep making more of them, it might be meant as a sort of work horse meant to get lots of anti-ship missiles in the skies. With all the tech and gizmos, it'll probably make it good enough for their intended role if in great enough numbers. They still have the H-20 bomber program which is supposed to become their so-called B-2 equivalent.


  • 0

#47 KV7

KV7

    Crew

  • Members
  • PipPip
  • 1,818 posts

Posted 25 November 2017 - 1905 PM

If they keep making more of them, it might be meant as a sort of work horse meant to get lots of anti-ship missiles in the skies. With all the tech and gizmos, it'll probably make it good enough for their intended role if in great enough numbers. They still have the H-20 bomber program which is supposed to become their so-called B-2 equivalent.

I think there is always a utility in even very basic platforms with large payload and range. The basis mechanics and engineering of large subsonic aircraft is a mature technology with very little prospect for improvement. 


  • 0

#48 JasonJ

JasonJ

    nemui

  • Members
  • PipPip
  • 10,200 posts
  • Gender:Male
  • Location:doko da?!
  • Interests:Sleeping

Posted 26 November 2017 - 0939 AM

If they keep making more of them, it might be meant as a sort of work horse meant to get lots of anti-ship missiles in the skies. With all the tech and gizmos, it'll probably make it good enough for their intended role if in great enough numbers. They still have the H-20 bomber program which is supposed to become their so-called B-2 equivalent.


I think there is always a utility in even very basic platforms with large payload and range. The basis mechanics and engineering of large subsonic aircraft is a mature technology with very little prospect for improvement.

"If it isn't broken, why fix it?" or something like that.
  • 0

#49 Josh

Josh

    Crew

  • Members
  • PipPip
  • 14,102 posts
  • Gender:Male
  • Location:New York City

Posted 26 November 2017 - 1226 PM

If they keep making more of them, it might be meant as a sort of work horse meant to get lots of anti-ship missiles in the skies. With all the tech and gizmos, it'll probably make it good enough for their intended role if in great enough numbers. They still have the H-20 bomber program which is supposed to become their so-called B-2 equivalent.


It definitely is intended as an anti shipping platform as one of its primary purposes. It has six hard points for either super sonic AShMs or else long ranged sub sonic land attack missiles; these are its primary armaments. They already have enough of them to be effective as an anti shipping platform; even a dozen would still carry over seventy missiles. It retains the top speed and RCS of its ancestor Tu-16 though, so it better have an escort or operate out of fighter and SAM range.
  • 0

#50 Josh

Josh

    Crew

  • Members
  • PipPip
  • 14,102 posts
  • Gender:Male
  • Location:New York City

Posted 26 November 2017 - 1230 PM

If they keep making more of them, it might be meant as a sort of work horse meant to get lots of anti-ship missiles in the skies. With all the tech and gizmos, it'll probably make it good enough for their intended role if in great enough numbers. They still have the H-20 bomber program which is supposed to become their so-called B-2 equivalent.


I think there is always a utility in even very basic platforms with large payload and range. The basis mechanics and engineering of large subsonic aircraft is a mature technology with very little prospect for improvement.


"If it isn't broken, why fix it?" or something like that.


The H-6K uses Russian turbofans. I suspect the answer is much more 'this is the best we can do right now'. For all of the talk of the Chinese being ten feet tall, they are just now building their first MPA (based on a Russian design with US help in pressurizing the airframe IIRC) and their first strategic airlifter (which looks very much like an Il-76). They have achieved success in producing some weapon types but are still generations behind in others. They've been playing catch up for decades and had a decimated engineering and education base due to the Great Leap Forward and Cultural Revolution. I think people underestimate how hard its been for them to establish their technological base and how focused it had to be to get where they are now.

Edited by Josh, 26 November 2017 - 1230 PM.

  • 0

#51 KV7

KV7

    Crew

  • Members
  • PipPip
  • 1,818 posts

Posted 26 November 2017 - 1802 PM

 

 

If they keep making more of them, it might be meant as a sort of work horse meant to get lots of anti-ship missiles in the skies. With all the tech and gizmos, it'll probably make it good enough for their intended role if in great enough numbers. They still have the H-20 bomber program which is supposed to become their so-called B-2 equivalent.


I think there is always a utility in even very basic platforms with large payload and range. The basis mechanics and engineering of large subsonic aircraft is a mature technology with very little prospect for improvement.

"If it isn't broken, why fix it?" or something like that.

 

A really good design and engineering effort using exotic materials and an expensive R&D program might for example give you a 15 % reduction in fuel consumption and 30% increase in range or something like that, and then you have virtually no more room for improvement as you are brushing up against hard limits of physics. It is a small gain in comparison to the advantages attainable by incremental improvement in other areas ; eg. radar, munitions, etc.

I.e. a modernised H-6 carrying some very modern hypersonic cruise missiles may be just as deadly and vastly cheaper than a B-2 using a less sophisticated munition.

 


Edited by KV7, 26 November 2017 - 1803 PM.

  • 0

#52 Mr King

Mr King

    Fat Body

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 18,900 posts
  • Gender:Male
  • Location:Muppetville

Posted 26 November 2017 - 1920 PM

It is interesting to note that on the new Chinese stealth aircraft, at least the ones they have shown, there appears to be no thermal management at the rear, to my uneducated eye. The F-35 from the US seems to be in the same boat. The F-117, the B-2, and the F-22 all show an effort to reduce the thermal signature, why not on the F-35, and why not on these Chinese aircraft? Also now that I think of it the Pak-Fa appears to have no thermal management either. 

 

FC-31 test flight

 

lLxNMLp.jpg


  • 0

#53 KV7

KV7

    Crew

  • Members
  • PipPip
  • 1,818 posts

Posted 27 November 2017 - 0114 AM

It is interesting to note that on the new Chinese stealth aircraft, at least the ones they have shown, there appears to be no thermal management at the rear, to my uneducated eye. The F-35 from the US seems to be in the same boat. The F-117, the B-2, and the F-22 all show an effort to reduce the thermal signature, why not on the F-35, and why not on these Chinese aircraft? Also now that I think of it the Pak-Fa appears to have no thermal management either. 

 

FC-31 test flight

 

lLxNMLp.jpg

They probably think in combat situation there is going to be after-burning, so little can be done to lower thermal signature.


Edited by KV7, 27 November 2017 - 1617 PM.

  • 0

#54 Josh

Josh

    Crew

  • Members
  • PipPip
  • 14,102 posts
  • Gender:Male
  • Location:New York City

Posted 27 November 2017 - 0922 AM

At the end of the day thermal management requires weight. All of the types you listed were attack types that could neglect performance except the F-22, and even then I think the IR reduction is limited to the 2-D thrust vectoring nozel - ie, the thermal management is somewhat integrated into the thrust vector and is possible specifically because it vectors in the vertical plane only, allowing a spread out rectangular nozzle. So a lot of compromises have to be made to spread out your IR plumb, and as noted if you're reheating all of that is for naught. Again, F-22 is an exception in that it was designed to supercruise at very high altitude (non-variable engine inlets).

Edited by Josh, 27 November 2017 - 0923 AM.

  • 0

#55 Loopycrank

Loopycrank

    Crew

  • Members
  • PipPip
  • 623 posts

Posted 27 November 2017 - 1412 PM

It's really hard to guess what total production will be.

 

Anyway, maybe this image is useful, probably J-10B. Can its radar quality or capabilities be speculated with this?

j-10bmaybe.jpg

https://www.facebook...?type=3

 

We can discern a few things from this picture.

The first thing to note is that the planar radar array appears to be fixed, with no mechanical gimbal to steer it.  That definitely means it's an electronically steered array.  Now, whether it's a PESA with a single wave generator and and phase-shifting elements in front or an AESA with an array of active elements on a single plane, we simply can't tell from the picture.

That said, there are some PESA and AESA arrays that have mechanical gimbals to allow them to pivot to the side to cover more area.  SU-35's radar does this.

 

Note also that the face of the array is angled back a few degrees from the vertical.  That's an old trick for reducing RCS.

 

The performance of the radar will be a function of how big it is, what wavelength it operates in, how well-made the electronic hardware is and how good the signal processing software is.  We can make a pretty good guess on that first factor, and increasingly wild-assed guesses on those other factors.  My personal guess is that it's nowhere near as good at a modern Western-made AESA.  The Russians were showing off their best radars at trade shows and bragging about SAR resolution that was roughly equivalent to mid-1990s US stuff, so unless the Chinese have a huge leg up on the Russians in avionics (unlikely; why would they be buying SU-35s if their stuff is already better?), then their electronic hardware and signal processing are probably a decade or two behind the US.  That said, this doesn't mean that these radars are directly equivalent to a 1990s US set; they have electronically steered antennas, so they most likely enjoy better scan times and ECCM.

 

Looks like an AESA, but I don't think that's particularly news.

 

No way to tell if it's AESA or PESA.  Rumint is that it's AESA.

 

It is interesting to note that on the new Chinese stealth aircraft, at least the ones they have shown, there appears to be no thermal management at the rear, to my uneducated eye. The F-35 from the US seems to be in the same boat. The F-117, the B-2, and the F-22 all show an effort to reduce the thermal signature, why not on the F-35, and why not on these Chinese aircraft? Also now that I think of it the Pak-Fa appears to have no thermal management either. 

 

 

 

There appears to be no thermal management yet.  Remember, these are still prototypes and they're still flying with the last-generation engines.  That means WS-10 for the J-20, which is basically an F100/AL-31 equivalent, and RD-93 for the J-31, which is like a very poor man's F404.

 

Designing fighter jet engine nozzles isn't easy.  Those things have to withstand tens of tons of thrust, massive thermal loading, and still remain very light.  So it's probably easiest to just leave the old nozzles on the interim engines instead of screwing around with things right now in the interest of getting all the flight testing done quickly.

 

The definitive, mass-produced engines are likely to have some IR reduction measures.  My guess is that they'll have serrated nozzle petals like the new SU-57 engine and the F135:
Pay5onw.jpg

For the record, the F135 does have signature reduction measures, they just work a little differently than the F119.  Those sawtooth shapes reduce radar reflections and also add a bit of turbulence to the air around the nozzle eflux.  This cools and disperses the exhaust and so reduces IR signature.  The F-35 also has an engine bay cooling system and some sort of system of radar blockers installed in the rear of the engine to prevent radar returns from the turbine blades when view from the rear.  I have no idea how that could possibly work without melting, but Pratt and Whitney have mentioned it several times in their literature.

Once the J-20 and J-31 get their definitive engines, I think we will see the Chinese equivalents of these technologies, whatever those might be.

 

 

 

They probably think in combat situation there is going to be after-burning, so little can be done to lower RCS.

 

 

Afterburning increases infra-red signature, not RCS, unless the aircraft is contrailing.

 

At the end of the day thermal management requires weight. All of the types you listed were attack types that could neglect performance except the F-22, and even then I think the IR reduction is limited to the 2-D thrust vectoring nozel - ie, the thermal management is somewhat integrated into the thrust vector and is possible specifically because it vectors in the vertical plane only, allowing a spread out rectangular nozzle. So a lot of compromises have to be made to spread out your IR plumb, and as noted if you're reheating all of that is for naught. Again, F-22 is an exception in that it was designed to supercruise at very high altitude (non-variable engine inlets).

 

I think you're a bit confused.  IR reduction is not limited to 2D nozzles by any means, although it was the favored approach for US designers for some time.  In fact, the Russians tried rectangular nozzles on a testbed SU-27:

96c142beda656e975355b337cfb92702.jpg

 

Rectangular nozzles have a much smaller thermal signature, but they're also much heavier and produce slightly less thrust due to inefficiencies.  It could well be that the IR masking approach of the F135 engine is just better, achieving similar results for fewer compromises.

 

The fixed inlets of the F-22 aren't for supercruise.  Fixed inlets hurt supersonic performance.  The fixed inlets are for stealth.


  • 0

#56 bfng3569

bfng3569

    Junior Member

  • Members
  • PipPip
  • 174 posts

Posted 27 November 2017 - 1453 PM

considering the heat output from the rear of a jet engine, how effective is it really?

especially on a fighter sized aircraft that is designed to maneuver and for speed vs a bomber or a strictly subsonic attack aircraft (F-117).
  • 0

#57 Josh

Josh

    Crew

  • Members
  • PipPip
  • 14,102 posts
  • Gender:Male
  • Location:New York City

Posted 27 November 2017 - 1524 PM

I think you're a bit confused.  IR reduction is not limited to 2D nozzles by any means, although it was the favored approach for US designers for some time.  In fact, the Russians tried rectangular nozzles on a testbed SU-27:

96c142beda656e975355b337cfb92702.jpg
 
Rectangular nozzles have a much smaller thermal signature, but they're also much heavier and produce slightly less thrust due to inefficiencies.  It could well be that the IR masking approach of the F135 engine is just better, achieving similar results for fewer compromises.
 
The fixed inlets of the F-22 aren't for supercruise.  Fixed inlets hurt supersonic performance.  The fixed inlets are for stealth.


Sorry, I shouldn't have said 'only', but the 2D nozzles are the most obvious IR reduction, and I think what specifically was being discussed. I'm not aware of what other IR reduction tech was used in the F-22; if there's anything else in open source I'd like to know.

My comment about the lack of variable geometry inlets was that the F-22 sacrifices these* for low RCS and that it can do so because it is more of a single purpose interceptor than a fighter. Because of that, it has a very high cruise speed at high altitude and would likely not need its afterburner for engagements. But that is a unique profile for an aircraft.

*Its worth noting the B-1 does as well, but that aircraft optimizes its fixed inlets for low level performance. That's why the B-1B lacks the B-1A high altitude top speed.
  • 0

#58 JasonJ

JasonJ

    nemui

  • Members
  • PipPip
  • 10,200 posts
  • Gender:Male
  • Location:doko da?!
  • Interests:Sleeping

Posted 27 November 2017 - 1830 PM

Thank you for that post Loopycrank.
  • 0

#59 KV7

KV7

    Crew

  • Members
  • PipPip
  • 1,818 posts

Posted 27 November 2017 - 1837 PM

Yes I meant IR emissions.


  • 0

#60 Loopycrank

Loopycrank

    Crew

  • Members
  • PipPip
  • 623 posts

Posted 27 November 2017 - 2215 PM

The F-22 also has some sort of IR-reducing paint.  Ever since the 1980s, IR seeker heads on missiles have been sensitive enough to lock on to an aircraft just from the heat of friction with the air on the front of the aircraft.  So, realistically, I think that the IR reduction measures on fifth-generation fighters will only serve to reduce the range at which IR-guided missiles can lock on, and quite likely not by that dramatic of an amount (at least when compared to the reductions in radar detection and lock on range).

 

The configuration of the flight control surfaces of the Raptor is also significant.  Those gigantic vertical stabilizers and horizontal surfaces shroud the exhaust plume from a fair number of angles of approach.


  • 0




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users