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Re: J-20 goes operational again

Unread postPosted: 09 Oct 2019, 17:33
by milosh
weasel1962 wrote:The tomcats may have benefited from the F-111 experience.


On YT you have excellent F-14 presentation done by back then Grumman vice president he was clear they learned a lot from F-111, he said if there wasn't F-111 we wouldn't be able to make F-14 as good as it is.

Re: J-20 goes operational again

Unread postPosted: 16 Oct 2019, 01:48
by inst
One topic that's pissed off both Chinats and neutral observers of the J-20 on SDF recently is discussion of the J-20's inlets.

We know that the Al-31 cannot provide sufficient thrust at altitude for the Su-27 with its variable inlets. The drag estimated for about 35,000 FT to at the Mach barrier is about 20,000 lbs. To reach Mach 1.4, you'd need about 25,000 pounds. The AL-31, at best, can do something like 60.5 kN with 2 engines (13,500 pounds) at that altitude and at Mach 1.1.

Is it possible that the Al-31 / WS-10 can do so at altitude given larger inlets (greater initial airflow), longer inlet length (greater space for the diffuser to do its work), as well as bypass ducts (as on the F-22) to bleed off low-speed excess airflow?

The total inlet length, ignoring geometry, is around 8-8.5 meters on the J-20, vs about 5 meters on the F-22.

Suspected bypass ducts on the J-20:

Image

https://www.quora.com/What-are-these-op ... of-an-F-22

Known bypass ducts on the F-22:

Image
Image

Re: J-20 goes operational again

Unread postPosted: 16 Oct 2019, 13:19
by sferrin
inst wrote:Suspected bypass ducts on the J-20:

Image


Where? And suspected by who? All I'm seeing are panel edges. Bypass doors are pretty obvious.

RTX2KDN7%20(1).jpg

Re: J-20 goes operational again

Unread postPosted: 18 Oct 2019, 15:52
by inst
You can see the discolored tiles that form a band. But DSI inlets don't have bypass, right? Except for the bypass ports in front of the main inlet.

Re: J-20 goes operational again

Unread postPosted: 18 Oct 2019, 18:00
by XanderCrews
milosh wrote:
weasel1962 wrote:The tomcats may have benefited from the F-111 experience.


On YT you have excellent F-14 presentation done by back then Grumman vice president he was clear they learned a lot from F-111, he said if there wasn't F-111 we wouldn't be able to make F-14 as good as it is.



Image

Re: J-20 goes operational again

Unread postPosted: 19 Oct 2019, 09:03
by element1loop
J-20 Jets Showcase Missiles

(Source: Global Times; issued Oct 18, 2019)

At an air show in Changchun this week, the Chinese Air Force displayed two J-20 fighters carrying short-range air-to-air missiles which rotated out from their side missile bays, where they are stored to maintain the aircraft's stealth. (PLA photo) China's most advanced fighter jet, J-20, once again revealed its missiles at the Chinese Air Force's "open day" event on Thursday, which also showcased the outstanding flight performances of a number of the PLA's warplanes. The open day, which runs from Thursday to Monday in Changchun, Northeast China's Jilin Province, is part of celebrations to commemorate the 70th anniversary of the founding of the Chinese People's Liberation Army (PLA) Air Force.

A pair of J-20 stealth fighter jets flew during the event's flight performance on Thursday morning. Each of them showcased two short-range combat missiles, which rotated out from their side missile bays, where they were usually stored to maintain the aircraft's stealth capability. This is only the second time the J-20 has showcased its missiles. The first was at the 2018 edition of Airshow China in Zhuhai, South China's Guangdong Province. The aircraft did not open its main weapon bay on Thursday. A series of aerobatic maneuvers, including high-speed dives, climbs and rolls from the country's most advanced fighter jets marveled the crowd. The maneuvers were combat-oriented, as each one had a tactical meaning and were used in actual combat scenarios to gain a superior position or avoid an attack, analysts said. ...

https://www.defense-aerospace.com/artic ... siles.html


Image

Chinese PL-10E*
Image

French MICA
Image

* Any similarity is purely coincidental.

Re: J-20 goes operational again

Unread postPosted: 19 Oct 2019, 17:04
by sferrin
inst wrote:You can see the discolored tiles that form a band.


Yeah, that doesn't make them bypass doors. They're pretty obviously just panel lines. The F-35 has stuff like that all over the upper side too. They aren't bypass ducts either. Now who says they're "suspected to be bypass ducts"? Which source.

Re: J-20 goes operational again

Unread postPosted: 19 Oct 2019, 22:03
by charlielima223
element1loop wrote:
Chinese PL-10E*
Image

French MICA
Image

* Any similarity is purely coincidental.


I believe that form follows function but I also believe the term "copy right" and its definition doesn't translate to Mandarin and Cantonese.

Re: J-20 goes operational again

Unread postPosted: 20 Oct 2019, 02:05
by weasel1962
Again, if merely the presence of wings means they copied, then every plane is a copy. If that's the standard, because the f-35b can take off vertically would mean it's also a copy. Colonel Sanders would have copied the Macdonalds burgers because they have the same overall shape. I think clearly the 2 main items the rocket motor and seeker are clearly different, the location, shape and size of the strakes, missile would mean different aerodynamics.

What is interesting is that of all the missiles the Chinese could have "copied" e.g aim-9/python/r-73, they chose the mica design. Why? Bay size constraints?

Re: J-20 goes operational again

Unread postPosted: 20 Oct 2019, 03:51
by element1loop
weasel1962 wrote:Again, if merely the presence of wings means they copied, then every plane is a copy. ... What is interesting is that of all the missiles the Chinese could have "copied" e.g aim-9/python/r-73, they chose the mica design. Why? Bay size constraints?


I said "similarity", not copy.

Re: J-20 goes operational again

Unread postPosted: 20 Oct 2019, 10:49
by weasel1962
charlielima223 wrote:I believe that form follows function but I also believe the term "copy right" and its definition doesn't translate to Mandarin and Cantonese.


In totally irrelevant trivia, the word "right" (as in left-right) is actually pronounced as "you" in mandarin. thus copy right would be to copy you. Potentially explaining the cultural difference.

Re: J-20 goes operational again

Unread postPosted: 02 Nov 2019, 10:38
by element1loop
Images show J-20 fighter fitted with new engines

Andreas Rupprecht, Mainz - Jane's Defence Weekly

01 November 2019

Images have emerged on Chinese online forums showing a Chengdu Aircraft Industry Group (CAIG) J-20 fifth-generation multirole fighter aircraft equipped with new engines. The photographs, which emerged in late October, show a J-20 painted in yellow primer both in the air and on the ground at Chengdu-Huangtianba airfield, the location of the CAIG manufacturing facility.

The new engine, the exact designation of which has not been disclosed, appears to be a variant of the indigenous Liming WS10A Taihang engine and features serrated afterburner nozzles to enhance its stealth capability. This engine variant was first tested on J-20 prototype number ‘2021’ on 19 September 2017 and then on prototype ‘2022’ in January 2018, after which the aircraft were transferred to the China Flight Testing Establishment at Xian-Yanliang airbase.

(151 of 490 words)


http://globalmilitaryreview.blogspot.co ... r-jet.html

Re: J-20 goes operational again

Unread postPosted: 06 Nov 2019, 04:07
by weasel1962
This was taken from a Chinese forum that formed the source of the Rupprecht article.
J-20 WS-10C.png


Also summarized the article below on the WS-10 variants.
https://www.china-arms.com/2019/09/ws-1 ... -variants/

WS-10 [2005] – J-11 (prototype only)
WS-10A [2005] – J-10/J-11B (few installed)
WS-10B [2008] – J-10C
WS-10B2 – J-16 (more than 200 engines installed)
WS-10B TVC – J-10B (air show exhibit only)
WS-10H – J-15 (test only)
WS-10C – J-20

Re: J-20 goes operational again

Unread postPosted: 06 Nov 2019, 05:13
by Corsair1963
j20L.jpg

Re: J-20 goes operational again

Unread postPosted: 06 Nov 2019, 15:20
by mixelflick
Well this should be interesting..

Who gets "stage 2" engines operational on their fighter(s) first? The Russians with the SU-57, or the Chinese with the J-20?

I'm betting on the Chinese..