J-20 goes operational again

Military aircraft - Post cold war aircraft, including for example B-2, Gripen, F-18E/F Super Hornet, Rafale, and Typhoon.
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inst

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Unread post20 Sep 2019, 19:52

Russia has very good engineers and scientists, it's mainly funding and social structure that holds them back.

That said, the Chinese are about at parity when it comes to naval radars, using a larger (5 meter or so) radar on the Type 055 vs the radars on the Arleigh Burke Flight IIIs, with both claimed to be using Gallium Nitride. We've heard little similar from the Russians, and the AESA they've shown seem to have significantly lower module counts (1500) than comparable Western systems. Comparing back to the Chinese, the J-20 prototype radar had about 1850 T/R modules while the F-22 radar had about 2000 T/R modules. So the module density isn't that far behind, and claimed radar performance is 50% detection chance at 450 km of 0 dBsm, which seem to tie into comparable American fighter AESAs of similar aperture.

@weasel1962: that's one of the reasons the Russians are rumored to be running all-metal construction, i.e, they're sanctioned out of composites.
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babybat{}.net

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Unread post20 Sep 2019, 22:12

inst wrote:that's one of the reasons the Russians are rumored to be running all-metal construction, i.e, they're sanctioned out of composites.


But Russia has domestic composites industry..
Example: https://en.umatex.com/
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milosh

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Unread post21 Sep 2019, 08:31

inst wrote:We've heard little similar from the Russians, and the AESA they've shown seem to have significantly lower module counts (1500) than comparable Western systems. Comparing back to the Chinese, the J-20 prototype radar had about 1850 T/R modules while the F-22 radar had about 2000 T/R modules.


Very simplistic pov. You need to count nose size also, Su-57 have smaller nose space for main radar then F-22 and J-20 have biggest nose of all stealths in fact if J-20 have only 1850 modules that is quite small if you look size of nose.

Also Su-57 have side arrays which take space, power and cooling but they are quite useful.

inst wrote:@weasel1962: that's one of the reasons the Russians are rumored to be running all-metal construction, i.e, they're sanctioned out of composites.


Su-57 never used lot of composite in structure it use them mostly as skin. It is very similar to F-22 in construction, both are metal construction but in F-22 titanium is dominant while in Su-57 it is aluminium.
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babybat{}.net

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Unread post21 Sep 2019, 10:34

milosh wrote:Su-57 never used lot of composite in structure it use them mostly as skin. It is very similar to F-22 in construction, both are metal construction but in F-22 titanium is dominant while in Su-57 it is aluminium.


Official data:
PCM = 22-26%;
Steels = 10.7%;
Al = 40.5-44.5%;
Ti = 18.6%.
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madrat

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Unread post21 Sep 2019, 11:45

Could be a sign the composite industry is immature...
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weasel1962

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Unread post21 Sep 2019, 15:34

babybat{}.net wrote:
inst wrote:that's one of the reasons the Russians are rumored to be running all-metal construction, i.e, they're sanctioned out of composites.


But Russia has domestic composites industry..
Example: https://en.umatex.com/


Exactly the point. Umatex produces composites with tensile strengths up to t700, not t800 or higher.
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milosh

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Unread post21 Sep 2019, 20:46

babybat{}.net wrote:
milosh wrote:Su-57 never used lot of composite in structure it use them mostly as skin. It is very similar to F-22 in construction, both are metal construction but in F-22 titanium is dominant while in Su-57 it is aluminium.


Official data:
PCM = 22-26%;
Steels = 10.7%;
Al = 40.5-44.5%;
Ti = 18.6%.


Thanks, as I said very similar as F-22 but Ti and Al change positions:

Titanium 64 (Ti-64) 36%
Thermoset Composites 24%
Aluminum (Al) 16%
Other Materials* 15%
Steel 6%
Titanium 62222 (Ti-62222) 3%
Thermoplastic Composites >1%
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babybat{}.net

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Unread post22 Sep 2019, 07:04

weasel1962 wrote:Exactly the point. Umatex produces composites with tensile strengths up to t700, not t800 or higher.


It was just an example) Of course, polyacrylonitrile thread for pak-fa program is not produced by Umatex, but by VNIISV.
Samples of the t-800 analogue to replace Chinese SYT55-12K for the mc-21 program already exist, but mass production will only begin within the next two years. Obviously, Russia is lagging behind in the field of modern composite materials, but not so critical.
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charlielima223

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Unread post22 Sep 2019, 07:19

milosh wrote:
Also Su-57 have side arrays which take space, power and cooling but they are quite useful.



Exactly how useful could they be? The side looking radar arrays, or at least the space that they intend to take isn' that big...
Image
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weasel1962

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Unread post22 Sep 2019, 07:38

babybat{}.net wrote:
weasel1962 wrote:Exactly the point. Umatex produces composites with tensile strengths up to t700, not t800 or higher.


It was just an example) Of course, polyacrylonitrile thread for pak-fa program is not produced by Umatex, but by VNIISV.
Samples of the t-800 analogue to replace Chinese SYT55-12K for the mc-21 program already exist, but mass production will only begin within the next two years. Obviously, Russia is lagging behind in the field of modern composite materials, but not so critical.


Which may explain why su-57 mass production will only happen later.
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milosh

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Unread post22 Sep 2019, 07:45

charlielima223 wrote:
milosh wrote:
Also Su-57 have side arrays which take space, power and cooling but they are quite useful.



Exactly how useful could they be? The side looking radar arrays, or at least the space that they intend to take isn' that big...
Image


Wider scanning field and ability to guide missile while maneuvering. F-22 would have them also, there is space for them.
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charlielima223

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Unread post22 Sep 2019, 22:40

milosh wrote:Image

Wider scanning field and ability to guide missile while maneuvering. F-22 would have them also, there is space for them.


From what I've heard the extra weight and power usage for the side radar arrays were not deemed to be that beneficial. The F-22s side radar arrays would be roughly the same size as that found on the PAKFA (and if installed would be more advanced at this point).
With such a small radar the range, scan area, and beaming would not be any where near useful especially for long range BVR type engagements. At certain point, size does matter. If guidence while maneuvering is concerned, isnt that what the F-22s IFDL is for or would be better? One F-22 takes the shot but have another undetected F-22 guide the missile. F-35 gets around the need for side looking radar arrays with the use of MADL in combination with is DAS.
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Corsair1963

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Unread post23 Sep 2019, 00:42

[quote="inst"]Russia has very good engineers and scientists, it's mainly funding and social structure that holds them back.

Russia lost many of her best Designers, Engineers, and Scientists after the collapse of the former Soviet Union. Then for the next twenty years had little in the way of funding. Which, isn't much better today....


Simple fact is Russia is not longer the USSR. Honestly, don't understand why so many don't get it??? :?
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weasel1962

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Unread post23 Sep 2019, 03:15

Other than Antonov, which builds mainly transport aircraft, the other aircraft manufacturers are Russia-based. The breakup of the USSR is more a symptom of the issues e.g. inefficient state-owned factories, than the cause. China's SOEs are no better, but as highlighted, resources are much more available.
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hornetfinn

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Unread post23 Sep 2019, 08:52

charlielima223 wrote:
milosh wrote:
Also Su-57 have side arrays which take space, power and cooling but they are quite useful.


Exactly how useful could they be? The side looking radar arrays, or at least the space that they intend to take isn' that big...


Those side radars will definitely give wider angular coverage at shorter ranges but that range is about 1/3 of the main radar range capability. So if the main radar can track some target 100 km away, the side radar can do the same 30 km away or so. So they can be useful against targets that Su-57 can get close enough. Not sure if that is enough to make them worthwhile.
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