Comparison of modern fighter turbofans

[Scott Kenny]

Forget about VTOL. The A and C would've been been better off with a twin F414 derivative.

2x OG F414-400 provide as much power while weighing less than one F135.

That wasn't an option. One airframe was to replace F16s, F18s, and AV8s (with limited modifications for carrier and VSTOL). End of discussion.

Which means you must have a single engine design to play.

If we were making one airframe to replace F16s and F18s, with a separate airframe to replace AV8s, then maybe we can play with twin engine designs. But I suspect that LockMart still would have submitted a single engine design, since they'd been wanting to do a single engine F22 since the ATF contest. And McAir was out after the A-12 lawsuit. Boeing might have won the Harrier replacement contract since their X32 design came out of the Common Affordable Lightweight Fighter (CALF) program.

 

[publiusr]

Have there been any large planes with very small additional jets for blown flaps---not enough for VTOL on its own ---but maybe useful in other ways?

 

[Scott Kenny]

Have there been any large planes with very small additional jets for blown flaps---not enough for VTOL on its own ---but maybe useful in other ways?

Only ones I'm positive of are the Shinmaywa US1 and US2. US1 has T64s for main power and a T58 for flap blowing, US2 has the RR AE2100s for main power and a T800 for blowing.

 

[TinWing]

Yeah that wasn't an option.

If only because of the requirement for STOVL. The shaft powered front fan arrangement was risky enough without the complication of it being powered by two engines instead of one. And how could it have been managed? Both F414s powering a single gearbox?

Moreover, a twin F414 F-35C would have looked entirely redundant compare to the Super Hornet.

Also, keep in mind that the Air Force JSF was supposed to cost roughly $25 million in mid 1990s dollars, basically the same price as a Block 52 F-16. That seems laughable today and probable was equally risible to the people in the know at the time.

In the end, the Koreans have demonstrated with the KF-21 what a more sensible and less ambitious CTOL F-35 might looked.

 

[Hanse]

If only because of the requirement for STOVL.

Yes, but it WAS a requirement.

 

[Scott Kenny]

Also, keep in mind that the Air Force JSF was supposed to cost roughly $25 million in mid 1990s dollars, basically the same price as a Block 52 F-16.

According to the Westegg Inflation Calculator, "What cost $25,000,000 in 1990 would cost $59,209,050.12 in 2023." (commas in numbers added) Also, an F16 Block 70, which is broadly close to the electronic capabilities of the F35, has a flyaway cost of $63mil.

So it's not as far off as it looks at first glance.

That seems laughable today and probable was equally risible to the people in the know at the time.

I'm still pretty sure I laughed at it then.

 

[Jacky]

F119 is 196 inches long and approximately 5,000 lbs

Sir, Is the 2-D thrust vectoring nozzle included in the F119 engine weight?

 

[F119Doctor]

Sir, Is the 2-D thrust vectoring nozzle included in the F119 engine weight?

Yes

 

[Hanse]

In the end, the Koreans have demonstrated with the KF-21 what a more sensible and less ambitious CTOL F-35 might looked.

Sure. But then you don't get the F-35B or C. (For sure not the B.)

 

[Scott Kenny]

Sure. But then you don't get the F-35B or C. (For sure not the B.)

I'm pretty sure the KF21 would make a decent F-35C.

And the F-35B should always have been a separate airframe.

 

[MadRat]

Different parts have grown and others shrank. Its not linear so any comparison is apples and oranges. Overall the TWR of engines, performance, or reliability improves. Between generations of the same engine base you maybe change 1-2. But between different technology generations all have improved.

 

[Airbus A340]

And what do you see in the photos that makes you think that? So far, all I’ve seen is the GE engine exhaust nozzle shroud move axially as the nozzle opens - which probably has something to do with modulation of the 3rd air stream, nothing to do with core airflow.

I have my suspicions as to how they are modulating the core to act as a small hard working unit for high bypass and as a big easy working unit for supercruise, but I’ll keep those to myself for now.

Can they shunt air from the second stream out of the core and into the bypass for supercruise while shunting more air from the first stream into the core? This takes a larger but less compressed stream into the core while providing a somewhat compressed stream in the bypass, increasing velocity. Then, for the subsonic region, the second stream takes what it gets from stream 1 and stream 2 sends as much as possible into the core. This increases OPR while making the bypass stream lower velocity. In the subsonic region, stream 1 should send as little as possible into stream 2. Is this how it works? I am trying to better understand how jet engines work.