18 tons probably the maximum thrust it can achieve during testing but in service it will be limited to around 16 tons to extend service life.
Chinese Engine Development
- Thread starter jackbh
- Start date
Dont forget China will operate with large fleets of both J-20 and J-20A. They can excel in different flight regimes.
Nope, per the engine TO, F119 (with nozzles and everything) weighs close to 5,000 lbs, even if we’re being generous and assume it’s 4,500 lbs and rounded up, that’s a T/W ratio of 7.78, and even with a round nozzle it would not increase to the 9 range.
Having a high T/W ratio is very difficult for a large engine especially one with a big core for supercruise. Usually thrust scales with square of the dimensions because of mass flow while weight scales with the cube. That’s why it’s hard to align the purported very high T/W ratio of 10+ for WS-15 with it being as supercruise focused as the F119 if it wants any kind of durability.
Well the thing is that rectangular nozzles decrease the thrust by 10%, (some even say 15%) meaning the F119 with round , conventional nozzles actually produces 38500lbf of thrust.
The 2D TVC nozzle is a bulky and heavy thing, and changing that to a conventional convergent-divergent nozzle should decrease the weight significantly.
So while in some areas the F119 is heavier but with some modifications it'll actually be not that much heavier than other military turbofans of that age (F110-GE-132=1840kg).
IMO, changing the 2D TVC nozzle with a normal, convergent-divergent non TVC nozzle should decrease the wight of the engine down to 2000kg and with a corresponding increase in thrust of 10% should result in a TWR of (38500/4400=)8.75
manqiangrexue
Brigadier
When it was said that rectangular nozzles decrease the thrust by 10-15% and a figure was given, is it clear if they meant that the decrease results in that figure or if it decreases 10-15% from that figure?
Rectangular nozzle decreases the thrust of engine no matter the engine. I've read the Soviets experimented with a rectangular nozzle on the Su-27, resulting in a 10% decrease of thrust.
If the F119 provides 35000lbf of thrust in its current form, swapping the rectangular nozzle for a normal one should increase the thrust by 10% too.
Square cubed law only holds if we are talking about the exact same dimensional ratios. 5th generation engines are stouter because they have fewer compression stages. Furthermore how powerful the compressor is also matters. If you can get more compression from the same capture area of air you can get more thrust without a larger dimension. Some combination of these factors are all employed in 5th generation engines.
For another example, the F135-PW-100 is based on the F119 but with a larger fan (F135 fan case outer diameter is about 43 inches compared to 40.5 inches for F119) with a bigger fan and has a round nozzle, but it weighs even heavier at about 6,400 lbs and has T/W ratio of 6.7, only has one more stage of turbines and stators than F119.
The Soviet flat nozzle is not directly comparable to the F119 nozzle, it’s much more crude and meant as a testbed with a lot less refinement. F119 flat nozzle saw a lot more full scale development and losses are about 5% compared to a round one.
The Soviet flat nozzle is not directly comparable to the F119 nozzle, it’s much more crude and meant as a testbed with a lot less refinement. F119 flat nozzle saw a lot more full scale development and losses are about 5% compared to a round one.
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5%? Unlikely. Most figures I've seen for 2D vectors are 15 to 20%. 3D loses less thrust at around 11%.
The PLAAF have not put the WS-10 TVC demo'ed by the J-10B into service and I think is because the penalties are pretty great to thrust.
so why not just use 3D nozzles to go in 2 directions?