Chinese Engine Development

Hyperwarp

Captain
Since the internal petals are exposed, how useful is the new sawtooth design on the nozzles for reducing RCS?

I was thinking the same thing. When looking at the F-35 LOAN, this thing on the WS-10 does not look very advanced.

The other thing is the rear radar blocker. it is a feature in the F-22 and F-35.

F-22:
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F-35:
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I assume these issues will be addressed with WS-15 variant of the J-20. Otherwise the rear RCS is going to be problem.
 

Hendrik_2000

Lieutenant General
Henri K take on the sighting of domestic engine
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When the J-20 finally uses Chinese engines
Since the first flight of the D-20 in January 2011, the debate about whether the Chinese stealth plane uses Russian engine or Chinese engine has never actually stopped.

As if the fact that their technological gem employs, if only temporarily, a foreign engine is synonymous with denigration, many Chinese refuse to the idea that the Chinese engines, whether the WS-15 planned in the long term or the WS-10 , had not yet reached maturity to power the J-20 program in its flight tests, see equipping the first pre-series aircraft, which have
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.

In constant search for technological independence, it is known that this situation does not please the Chinese decision-makers, let alone the Chinese military, to spend every year astronomical sums to import foreign engines. After the J-11B , J-11BS and J-16 , and the dedicated J-10B and J-15 prototypes, we wondered when the WS-10 engine, whose launch of development dates back 30 years ago now, will finally be installed on the J-20.

Rumors had emerged since early 2016 about the existence of a specific project at the Shenyang Aeroengine Research Institute (606) to develop certain aspects of WS-10 stealth.

At the beginning of July this year, a person working in the sector had also indicated that "for the next batch of J-20, it will be necessary to monitor the rear (ie the engines) of the aircraft because the shape and color will change ".

"Although this is not our final goal and there is no significant improvement on the engine's performance, the change is fully justified," she added.

And
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seems to have confirmed these affirmations however unofficial. Indeed, it shows a J-20, in yellow paint factory, equipped with two engines quite different from those that can be seen so far.

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New engines installed on a J-20, wearing factory yellow paint (Photo: 科 京 </s>)

After comparison with the engines in service in the Chinese air force, the primary flaps of the nozzle are typical of those of WS-10, and the secondary flaps are also different from those of AL-31FN acquired by China.

This would be a new variant of WS-10, specially adapted for the J-20 program.

Is it the famous WS-10-T2 , which would have inherited the Chinese FADEC designed for the WS-10B a post-combustion thrust of 13,200 kg, and benefited from improvements on the combustion chamber and blower structure and compressors of the WS-10G of 14,200 kg?

However, the installation is not complete since a transition part is missing, and the nozzle of this new WS-10 is in the form of a sawtooth, a measure to reduce its equivalent area radar (SER) as the Pratt & Whitney F-135 did before him.

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The F135-PW-600 engine from F-35B

Knowing that the incoming air flow varies from one engine to another, it is necessary that the engineers re-adapt the air intake of the airplane. Not to mention the difference in size, ie diameter and length for example, which requires additional design work on the rear part of the device.

There is reason to believe that this new J-20, fresh out of the factory because of the color of its coating and called a priori "state A2", should leave again in a long companion of tests in flight to validate to new the field of flight, and also the reliability and maintainability of the Chinese engine, for example.

So it would probably take a while longer to see the future J-20 series fly "operationally" with the Chinese engine.

To be continued.

Henri K.
 

siegecrossbow

General
Staff member
Super Moderator
I was thinking the same thing. When looking at the F-35 LOAN, this thing on the WS-10 does not look very advanced.

The other thing is the rear radar blocker. it is a feature in the F-22 and F-35.

F-22:
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F-35:
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I assume these issues will be addressed with WS-15 variant of the J-20. Otherwise the rear RCS is going to be problem.

At an expense to thrust though. Definitely will need to wait till WS-15.
 

Quickie

Colonel
I was thinking the same thing. When looking at the F-35 LOAN, this thing on the WS-10 does not look very advanced.

The other thing is the rear radar blocker. it is a feature in the F-22 and F-35.

F-22:
Please, Log in or Register to view URLs content!


F-35:
Please, Log in or Register to view URLs content!


I assume these issues will be addressed with WS-15 variant of the J-20. Otherwise the rear RCS is going to be problem.

Isn't that a flame holder?
 

superdog

Junior Member
Wow, somehow I missed it. The internal petals are familiar alright, especially in the way they close rather asymmetrically, which kind of puzzled me as to its purpose when I first saw them quite some time back.
Those pedals are free-moving so they can adapt to the pressure difference between the core exhaust and the surrounding airflow of an ejector nozzle. When the engine is not running and the aircraft not moving, the top pedals drop down due to gravity while the rest stay flush. When the engine is running, the nozzle will become symmetric and those pedals won't deflect at such a large angle.
 

siegecrossbow

General
Staff member
Super Moderator
Those pedals are free-moving so they can adapt to the pressure difference between the core exhaust and the surrounding airflow of an ejector nozzle. When the engine is not running and the aircraft not moving, the top pedals drop down due to gravity while the rest stay flush. When the engine is running, the nozzle will become symmetric and those pedals won't deflect at such a large angle.

One advantage of this design is that no additional mechanism is required to change the petal position. However, it is more prevalent on older engines.
 
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