China Flanker Thread II

[Lion]

And the funniest thing is F-22 the american superfighter has TVC nozzles, so to say China does not want TVC nozzles is just for a good laugh

I agree before J-31 appears, this sentence still valid for J-20 but with J-31 appearing in a almost similar configuration as F-22, TVC probably will help. We have already seen AVIC introducing plan / model to build a 9500KG engine with TVC nozzle.

 

[Engineer]

And the funniest thing is F-22 the american superfighter has TVC nozzles, so to say China does not want TVC nozzles is just for a good laugh

That's not funniest, but I will tell you what is. The funniest thing is that with F-35, the role in maneuvering is again taken away from TVN and the nozzle only operates during VTOL. What's more, the US doesn't retrofit older fighters with TVN even though the country is perfectly capable to do so. Likewise, countries that operate Eurofighter do not opt to have TVN installed. Those are signs of no confidence in TVN from leaders that are aerospace technologies. China shows little interest in AL-31FP or TVC version of AL-31FN, nor has China fitted its own TVN to existing aircraft. The claim that China wants TVN (from Russia) is nothing more than a laughable Russian fantasy.

 

[Engineer]

why China changed the denomination of J-11B to J-16, sounds like sukhoi changes Su-27KUB to Su-30?

should not be better say J-11C or J-11D?

J-11B is not J-16. J-16 is China's equivalent to Su-30 with more emphasis on surface attack.

 

[Quickie]

The J-20 requirement for TVC is questionable because of its canard design configuration as opposed to the F-22 and T-50. The J-31 could benefit from TVC but the benefits will only be incremental, perhaps less so than the larger F-22 and T50 (guessing on their sizes at this point), and have to be weighed against the associated more complicated maintenance involving TVC.

 

[NikeX]

Speaking of domestic high performance jet engines where is Chinese aerospace on the production of an engine capable of powering their new generation of fighters? Last time I looked this was the situation:

"..In an April 2011 interview, China Aviation Industry Corporation (AVIC) head Lin Zuoming noted that despite China’s rapid development as an aerospace power, the country’s ability to produce modern jet engines remains a glaring weakness. To address these shortcomings, AVIC is treating engine development as a high priority and plans to invest 10 billion RMB (US$1.53 billion) into jet engine research and development over the next 5 years."

Seems that Chinese engine makers are having problems in the following areas. What is the latest on Chinese efforts to overcome these problems?

–Precision cutting, welding, and machining, e.g., five-axis milling for production of turbine blades.

–Special materials blade production. China’s largest turbine blade production facility, located at Xi’an Aero-Engine, can now undertake mass-production of turbine blades made from superalloys, titanium alloys, cobalt alloys, and stainless steel. The turbine blade quality rate is now said to exceed 95%.

–Hollow fan blade production. China is entering the nascent stages of being able to produce hollow fan blades. Hollow titanium fan blades are 15-20% lighter than their equivalents and make an engine more fuel efficient. They also reduce rotating mass and allow a tactical aircraft engine to spool up more quickly during maneuvers.

–Greater automation. This improves standardization and efficiency.

–Process modeling. Computer-aided process modeling help manufacturers anticipate problems with materials, welds, and behavior of parts under heat stress. Flagging potential trouble spots before machines are started helps save time and money and also ultimately helps produce a higher quality, more durable engine.

–Enhanced ability to use numerically-controlled milling machines to produce turbine disks.

–Better ability to produce high-quality, standardized spare parts. Reliable access to such parts is essential to supporting aircraft performance, particularly at the high and unpredictable operational tempo inherent in many operational scenarios. Spare parts have traditionally represented an area of weakness in China’s aviation industry.

 

[MiG-29]

The J-20 requirement for TVC is questionable because of its canard design configuration as opposed to the F-22 and T-50. The J-31 could benefit from TVC but the benefits will only be incremental, perhaps less so than the larger F-22 and T50 (guessing on their sizes at this point), and have to be weighed against the associated more complicated maintenance involving TVC.

as a counter argument this is what a F-22 pilot says


F-22 test pilot Paul Metz:
"-All aircraft experience a loss of control effectiveness at supersonic speeds. To generate the same maneuver supersonically as subsonically, the controls must be deflected further. This, in turn, results in a big increase in supersonic trim drag and a subsequent loss in acceleration and turn performance-"

this equals higher RCS at supercruise too

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J-20 at supercruise will increase RCS and drag just by pure canard deflection

China has not the experience niether in manufacture of TCV nozzles niether in test flights that Sukhoi has just in the Su-27 program, only Lockheed Martin has it.


The Su-35 has engines already in production with a much more complex TVC nozzle system.

J-20 does not fly with TVC nozzles because no other chinese fighter does it.
No J-11B or J-16 does it

 

[Hendrik_2000]

All those fancy nozzle are crowd pleaser in Air Show but real life fighter engagement is something else. Everybody should be familiar by now the result of Red Flag exercise in US back in 2008

Yeah those Indian pilot with their Su 30MKI fancy move against plain vanilla F15

Just to refresh the memory listen to this

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[hmmwv]

Speaking of domestic high performance jet engines where is Chinese aerospace on the production of an engine capable of powering their new generation of fighters? Last time I looked this was the situation:

"..In an April 2011 interview, China Aviation Industry Corporation (AVIC) head Lin Zuoming noted that despite China’s rapid development as an aerospace power, the country’s ability to produce modern jet engines remains a glaring weakness. To address these shortcomings, AVIC is treating engine development as a high priority and plans to invest 10 billion RMB (US$1.53 billion) into jet engine research and development over the next 5 years."

Seems that Chinese engine makers are having problems in the following areas. What is the latest on Chinese efforts to overcome these problems?

The situation hasn't changed much really, engine is still a glaring weakness in AVIC compare to all the other aspects, and will remain so for the foreseeable future. They can make good engines, but at a high cost of time and money. Liming is getting better everyday though, the hundreds of WS10As in servie speaks for itself.

 

[Engineer]

The J-20 requirement for TVC is questionable because of its canard design configuration as opposed to the F-22 and T-50.

This. Not long ago, F-22 with TVC was defeated by Eurofighter which has no TVC. One of the reasons cited was that the F-22 over used its TVC. Here is a proof of the outcome:

The Rafale has also scored kills against the F-22, as these pictures show:

Unlike an aircraft with standard configuration, aircraft such as the J-20 have primary pitch control surfaces in front of the wing. The canards result in vortices over the wings that enhance lift. At the same time, all moving canards maintain low incidence angle with the oncoming air, thus maintaining minimal drag even when the aircraft is in high AoA, unlike stabilators. In short, such aircraft can make a tighter turn without suffering significant drag even without TVN.

As for control surfaces contributing RCS, this is completely meaningless when high maneuverability is exercised. An aircraft in high-G maneuvering implies the aircraft is in the process of dodging missiles or a dogfight. In other words, the aircraft is already seen, so there is no point in keeping a low RCS.

The J-31 could benefit from TVC but the benefits will only be incremental, perhaps less so than the larger F-22 and T50 (guessing on their sizes at this point), and have to be weighed against the associated more complicated maintenance involving TVC.

It is arguable whether there will be any benefit at all. People often forget about weight penalties when they talk about advantages of TVN, and the 310 being small will only magnify the issues. Gaining performance improvements with TVN while losing those improvements to weight would be a pointless exercise.

There are also significant penalties in maintenance, as an example the MTBO for AL-31FP is 1000 hours yet the MTBO for the TVN is only 500 hours. Remember, one reason why Germany lost to the Soviet was because Germany tanks were over complicated. Performance gains are pointless if the aircraft is a hangar queen.

Fluidic thrust vectoring is supposed to solve the weight and maintenance problems, but the idea is still a concept at this time and a working model is still pretty far away.

 

[Engineer]

The situation hasn't changed much really, engine is still a glaring weakness in AVIC compare to all the other aspects, and will remain so for the foreseeable future. They can make good engines, but at a high cost of time and money. Liming is getting better everyday though, the hundreds of WS10As in servie speaks for itself.

This is true. People like to jump at the opportunity to say China cannot design and build modern jet engines. The reality is that China can do both, but doing so requires enormous resources and focus at the national level. In comparison, western engine manufacturers make new engines like cakewalk, while still have enough resource left to research into new technologies.

Currently, China possess all the requirements to build a F-119 class engine, and the resulting product is the WS-15. What China needs now is money and practice. $1.53 billion may sound a lot, but it is nothing compared to the enormous fund that Western engine manufacturers gain from civilian sector. Western engine manufacturers also have enormous experience from building countless civilian engines, whereas the only experience China has right now is the WS-10. China won't get the experience it needs without practice in building 10~20 new turbofan engines.