Chengdu J-20 5th Generation Aircraft News & Discussions

[Ultima Thule]

Bro, I am asking the bypass ratio numbers and where you got them, so I can read them myself.

PLAAF promotion video showing 6 J-20 formation.

View attachment 415743

But with high bypasss ratio WS-10 engine J-20 can't have supercrusie capability, if J-20 want to super cruise J-20 needs low bypass engine

 

[帅的一匹]

But with high bypasss ratio WS-10 engine J-20 can't have supercrusie capability, if J-20 want to super cruise J-20 needs low bypass engine

Not sure, maybe they had made some modification in the later variant of WS10.

 

[Deino]

#06

 

[Ultima Thule]

Not sure, maybe they had made some modification in the later variant of WS10.

Sorry Sir I'm talking about WS-15

 

[52051]

Supercrusie is good, but even without of it, according to TV interview of pilots of J-20, J-20 with current engine configure is still extremely agile and very easy to control, and the fighter simply dominate at supersonic speed range and dominate any 3rd gen fighters.

Of cause, without WS-15, many characters of fighter will be comprised, but according to chief designer Yang Wei, the most important feature of this fighter is data-fusion and stealth, and it will be rather stupid to engage in dog-fight with a 4th gen fighter, so the problem will not be that serious, its like without WS-15 J-20 will be a african lion but with it could be a Serbia tiger with it, but since most of your opponents are at dog level, so tiger or lion, it may not make much a difference at all.

 

[Beast]

I remembered they said WS-10 and variants were based on a US engine (non-military) design many years ago.

WS-10 core is based on CFM-56 which is a US design. But as I say, WS-10 is just a designation. If AVIC decide to used this designation on this upgrade AL-31F clone. So be it, I don't think AVIC will be so open by a clone. That is reason why so little info abt it.

 

[ZeEa5KPul]

#06

View attachment 415766

I die a little inside each time I see those ratty, ghetto nozzles. Where's the WS-15!? *Argh*!!

Just serrate them or something, if only for aesthetics!

 

[ChineseTiger1986]

Bro, I am asking the bypass ratio numbers and where you got them, so I can read them myself.

PLAAF promotion video showing 6 J-20 formation.

View attachment 415743

It is based on the speculation, but the WS-15 should have much lower bypass ratio than the WS-10.

 

[Asoka]

It is based on the speculation, but the WS-15 should have much lower bypass ratio than the WS-10.

Some people would have disagreed with you.

"从歼20首飞, 发动机声音判断，绝对是新型的, 大涵道比发动机，它的涵道比, 超过歼10、SU27和F22三种战机" http://m.huanqiumil.com/news/60838_2.html

"一核多用，WS15是小涵道比歼20用的，WS20是大涵道比运20用的，"

The idea that WS15 has a low bypass ratio, is in comparison, with the huge transporter and airline engines, I believe.

In my opinion, the reason airline jet engines has a bigger thrust is because they have a gigantic fan, and most of the air, bypassed, the core of the engine, and sent to the back of the engine by the huge fan, and so they have a huge bypass ratio. The bypass ratio of the GE9x is 10:1. Most of the power come from the huge Fan. But a huge Fan like that of the GE9x is not suitable for a fighter plane's narrow fuselage, and therefore, not suitable for supersonic speed.

Notice the Huge Gigantic Fan, and the narrow core of the GE9x. A gigantic fan is great for fuel efficiency at subsonic speed, but of course, it stinks at supersonic speed. GE9X has a huge thrust of 450 to 470 kN.

 

[ChineseTiger1986]

Some people would have disagreed with you.

"从歼20首飞, 发动机声音判断，绝对是新型的, 大涵道比发动机，它的涵道比, 超过歼10、SU27和F22三种战机" http://m.huanqiumil.com/news/60838_2.html

"一核多用，WS15是小涵道比歼20用的，WS20是大涵道比运20用的，"

The idea that WS15 has a low bypass ratio, is in comparison, with the huge transporter and airline engines, I believe.

In my opinion, the reason airline jet engines has a bigger thrust is because they have a gigantic fan, and most of the air, bypassed, the core of the engine, and sent to the back of the engine by the huge fan, and so they have a huge bypass ratio. The bypass ratio of the GE9x is 10:1. Most of the power come from the huge Fan. But a huge Fan like that of the GE9x is not suitable for a fighter plane's narrow fuselage, and therefore, not suitable for supersonic speed.

Notice the Huge Gigantic Fan, and the narrow core of the GE9x. A gigantic fan is great for fuel efficiency at subsonic speed, but of course, it stinks at supersonic speed. GE9X has a huge thrust of 450 to 470 kN.

View attachment 415871

That was the earliest engine for the J-20 prototype, and we didn't know anything about the bypass ratio for the engine of the current production model.

 

[Asoka]

That was the earliest engine for the J-20 prototype, and we didn't know anything about the bypass ratio for the engine of the current production model.

Some eyewitness, in Chengdu reported the J-20's engine, has became very quiet, after the engine was changed around 2015. This would indicated, a larger bypass ratio, like that of the airline engines, which are very quiet compared to the roaring fighter jet engines.

GE9X is reported to be very quiet, so quiet that you can talk on your cellphone, while stand near it.

The huge air intakes of J-20 has room to supports, a large Fan, for its Turbofan engine.

 

[Ultima Thule]

Some eyewitness, in Chengdu reported the J-20's engine, has became very quiet, after the engine was changed around 2015. This would indicated, a larger bypass ratio, like that of the airline engines, which are very quiet compared to the roaring fighter jet engines.

GE9X is reported to be very quiet, so quiet that you can talk on your cellphone, while stand near it.

The huge air intakes of J-20 has room to supports, a large Fan, for its Turbofan engine.

but if J-20 has a high bypass ratio turbofan of WS-15 with high bypass ratio WS-15 J-20 can't super cruise

 

[Asoka]

but if J-20 has a high bypass ratio turbofan of WS-15 with high bypass ratio WS-15 J-20 can't super cruise

I am not saying WS-15 has a freaking high bypass ratio like that of GE9X. I am saying WS-15 has a higher bypass ratio than WS-10 and AL-31F. Don't confuse the two ideas.

I don't know, where is your idea of having higher bypass ratio, and you can't supercruise comes from.

Show me some links.

 

[Taygibay]

OK! Let's make things simple :

- The total mass of the airflow times the difference between exhaust speed and flight speed equals thrust.

- The high bypass of a turbofan allows better fuel economy at cruising speed and those engines are less noisy.

- The response time of a low bypass is better because it moves less air : "it shifts faster" ( combat essential ).

- Since no big fan to move slow air, less cross-section, vital for drag reduction to go faster easier ( & stealthier ).

- Lower bypass ratio produce less total thrust but more of it per kg of engine A.K.A better thrust to weight ratio.

- Lower bypass ratios perform best at higher speeds; high bypass ratios are optimized for high subsonic cruise.

- To hike thrust, fighters use afterburners ( higher nozzle speed ) and airliners maximize flow with high bypass.


Cores are, as some mates mentioned, often similar since as we showed the difference lies elsewhere.

I.E. GE F-110 to CFM-56 . . .
​

Have a great day all, Tay.

 

[Ultima Thule]

I am not saying WS-15 has a freaking high bypass ratio like that of GE9X. I am saying WS-15 has a higher bypass ratio than WS-10 and AL-31F. Don't confuse the two ideas.

I don't know, where is your idea of having higher bypass ratio, and you can't supercruise comes from.

Show me some links.

https://aviation.stackexchange.com/...itary-turbofan-engines-use-a-low-bypass-ratio
http://www.sailax.co.nz/wx/201501/a_Why_do_fighter_planes_use_low_bypass_turbofan_.html
https://defenseissues.net/2014/07/05/supercruise/