J-10 Thread III (Closed to posting)

[unknauthr]

Engine Airframe Combination

back in the 90's the russian do offer AL-41F,like F-119 and EJ-2000 the engine capable of supercruise, but China politely turn down the offer.
later russian offer improve AL-31F-3 (?) which is more powerful thrust than WS-10A,and able to performed supercruise,retrofit the existing SU-27/J-11 but China has to date no reply from the offer.

I would agree that obtaining access to a more powerful engine will be a key component if China expects to attain a useful supercruise capabilty. We should not loose sight, however, that supercruise is still very much a package deal - having as much to do with the airframe as it does with the engine.

A number of earlier generation fighters did have a modest supercruise capability - just by virtue of having a very low drag design. Being able to just barely supercruise (at around Mach 1.2 for example) with little or no payload offers very little tactical advantage. The US has emphasized for some time that to be meaningful, the airplane needs to be able to supercruise in excess of Mach 1.5 with an operational payload. In practical terms, that will tend to push the airplane towards internal weapons carriage.

As the article suggests, Wu's comments appear to be directed at the next generation of Chinese fighter (J-XX), and not at the aircraft flying today (J-10 or J-11 or their immediate derivatives). It's not just a matter of having a more powerful engine (although that too is important and necessary), but of matching the engine with a low-drag airframe that features internal missile bays.

What is not clear from Wu's comments is whether he is campaigning for a capability that he fears the J-XX team might otherwise loose sight of, or if this capability is already secure. Designing an airplane is always a trade between competing requirements. If they add too much weight, and grow the airplane a little too much to add range or payload - then they could potentially sacrifice any shot at a true supercruise capability. We'll just have to wait and see what ultimately rolls down the runway.

 

[plawolf]

The cynic in me can't shake the suggestion that the only reason the USAF chose Mach 1.5 is in order to disqualify the Typhoon from the rank of supercruisers.

Lets not get too carried away with dubiously set numbers and loose sight of what the whole point of supercruising is about - fuel economy.

I'm sure there are others who can explain it better then me, but different airframes have different transonic zones. This is because the airflow distortion caused when something approaches the sound barrier does not magically disappear as soon as the tip of a plane breaches the sound barrier. So a plane flying at M1.01 will stuffer the same buffeting and subsequent increase in fuel consumption as just before it breached the sound barrier.

Only after the entire airframe has passed through the sound barrier will the distorted airflow be left behind and fuel consumption drop to a level close to normal subsonic cruising speeds, but depending on the airframe, this might not happen until M1.1 for example.

So long as the entire airframe has passed through the sound barrier without needing to apply afterburners, than that technically has met the requirements of supercruise.

While being able to supercruise at M1.5 is obviously better the only managing M1.2, that difference is a matter of degrees instead of categories.

But the rest of your post is very well thought out though. Sorry, could not resist being pedantic on this issue.

 

[Delbert]

Can the J-10 outperform the Eurofighter Typhoon?

Is their any mock combats made between these aircrafts?

I hope I would be able to see one in the future. Just wanted to know who's better.

 

[HKSDU]

Can the J-10 outperform the Eurofighter Typhoon?

Is their any mock combats made between these aircrafts?

I hope I would be able to see one in the future. Just wanted to know who's better.

The only mockup with J-10 is the J-11. The J-10 haven't left he airspace of China, nor been used to participate in friendly mock up battles.

 

[unknauthr]

The cynic in me can't shake the suggestion that the only reason the USAF chose Mach 1.5 is in order to disqualify the Typhoon from the rank of supercruisers.

Lets not get too carried away with dubiously set numbers and loose sight of what the whole point of supercruising is about - fuel economy.

The operational objectives behind supercruise actually have nothing to do with fuel economy. A well designed, subsonic aircraft will always out-perform its supersonic counterpart in terms of range - because it does not have to contend with wave drag.

The operational advantages of supercruise were actually laid out in a paper published decades ago by German engineer Wolfgang Herbst. Herbst's study into future air combat needs concluded that the future air-to-air battlefield would be dominated by two classes of fighters: the transonic, post-stall capable dogfighter that he expected to dominate in visual range combat; and the supercruise capable fighter that was projected to dominate in the beyond visual range arena.

With regard to the former, Herbst's predictions have been overtaken by the development of helmet mounted sights and highly agile, high-off-boresight heat-seeking missiles. With regard to the latter, it was Herbst who effectively set the Mach 1.5 threshold for defining meaningful supercruise capability.

Modern air combat centers very much around energy management. A superior energy state gives an airplane the opportunity to choose the time and place where it will engage the enemy. This, not fuel economy, is what make supercruise so attractive.

 

[Delbert]

The only mockup with J-10 is the J-11. The J-10 haven't left he airspace of China, nor been used to participate in friendly mock up battles.

So does the PLAAF have any plans to conduct mock up battles with other western airforces?

 

[Blitzo]

So does the PLAAF have any plans to conduct mock up battles with other western airforces?

Apart from Pakistan, I doubt China will do so.

Both China and the West probably don't want to show each other their planes, and even if China wanted to join the Red Flag excercises I think the US would turn them down.

 

[mean_bird]

Apart from Pakistan, I doubt China will do so.

Both China and the West probably don't want to show each other their planes, and even if China wanted to join the Red Flag excercises I think the US would turn them down.

Pakistan doesn't/will not have permission to fly F-16s to china for exercises.

So any exercises would be against the decades old Mirages and J-7s. I think that is the reason they do not conduct these exercises in spite of such good friendship and military-to-military ties.

Things might change with the JF-17 and FC-20.

 

[AssassinsMace]

I've read that Chinese pilots have flown Pakistani F-16s as well as reported that Pakistani pilots have flown the J-10. Might learn something from that. And don't forget Pakistani pilots are pretty good according some in the US military.

 

[mean_bird]

Any such thing would have been un-official.

having one or two pilots sneak over and fly a plane is one thing( if that ever happened), but participating in an exercise is another.

Btw does China conduct regular exercises with Russia or any other country?