Shenyang FC-31 / J-31 Fighter Demonstrator

AssassinsMace said:

Anyone hear the KF-X is in trouble because it can't find a partner? What happened to Indonesia?

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Where did u hear it from? And I thought Turkey is in it too?

getready said:

Where did u hear it from? And I thought Turkey is in it too?

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There are threads in both CJDB and FYJ.

Engineer said:

The reason has more to do with simplicity. It is not impossible to achieve good performance with a serpentine inlet, but it takes a lot more effort than doing so with a straight one. Thus, the ability to employ an S-inlet on a fighter reflects a country's capabilities in aerospace technologies.

Aside from J-20, F-22 and F-35 also employ S-inlets. The lack of such inlet on the PAKFA is a sign that the designers didn't have the ability and funding to solve the technical challenges brought forth by the S-inlet. Sucking air through a radar blocker will reduce the efficiency of the engines, thus lowering the performance of the PAKFA.

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hahaha.

Look Su-47 has S ducts and internal weapons bays, in fact S ducts are not new all single engined fighters with side intakes have S ducts, commercial aircraft like L-1011, Boeing 727, Tu-154 also have S Ducts.

[video=youtube;3rm753XwTio]http://www.youtube.com/watch?v=3rm753XwTio&feature=related[/video]

S ducts are not new at all, missiles, commercial jets and fighters have them, LCA has S ducts, to cite one example.

However X-32 did not use S ducts, each designer uses what they think is the best solution.

PAKFA might have some performance degradation it is possible, however it reduces mass and weight thus this allows for a lower fuselage weight than S-37 Berkut.


However S ducting increases weight and in order to reduce it the short and curved S duct also degrades performance.

Which one is better is up to the designer`s parameters.

For Sukhoi S ducts are not worthed on PAKFA because they wanted a lighter and smaller fifth generation

Which system is better is only tested and proven in the battlefield, history will tell perhaps in the future which system is better.

Engineer said:

The reason has more to do with simplicity. It is not impossible to achieve good performance with a serpentine inlet, but it takes a lot more effort than doing so with a straight one. Thus, the ability to employ an S-inlet on a fighter reflects a country's capabilities in aerospace technologies.

Aside from J-20, F-22 and F-35 also employ S-inlets. The lack of such inlet on the PAKFA is a sign that the designers didn't have the ability and funding to solve the technical challenges brought forth by the S-inlet. Sucking air through a radar blocker will reduce the efficiency of the engines, thus lowering the performance of the PAKFA.

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Exactly, and I would expect it to be more aerodynamically "draggy"? Good looking GCI, I guess I just prefer a more conventional configuration aesthetically, as I did say the F-22 kinda had to grow on me, but now it seems like a natural extension of the F-15 style planform.

Less Thrust, More Drag, not the best IMHO.

MiG-29 said:

hahaha.

Look Su-47 has S ducts and internal weapons bays...

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The S-47 is another project where most of the work has already been done by the Soviet Union. The project began in 1983, and uses researches dated as far back as 1940. From :

Named Berkut, which translates to mean Golden Eagle or Royal Eagle, the S-37 bears an "S" rather than an "Su" designation because it is an experimental rather than production aircraft. Design of the aircraft, originally known as the S-32, began around 1983, and drew on many years of FSW research that had commenced in the former Soviet Union during the 1940s—initially using captured Nazi technology.

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While Russia was ultimately able to complete Soviet's dream and put this aircraft into the air, the aircraft nevertheless is a piece of mostly Soviet technology.

MiG-29 said:

in fact S ducts are not new all single engined fighters with side intakes have S ducts, commercial aircraft like L-1011, Boeing 727, Tu-154 also have S Ducts.

S ducts are not new at all, missiles, commercial jets and fighters have them, LCA has S ducts, to cite one example.

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Commercial airliners with S-ducts don't fly at supersonic speed or high angle of attack, and this is also the case with most cruise missiles. The LCA is a joke, with an extremely powerful engine for such an aircraft's size, yet still isn't able to meet requirements.

Whether S-duct as a concept is new is also entirely irrelevant, as it doesn't alter the fact that Sukhoi was unable put such a design on the PAKFA.

MiG-29 said:

However X-32 did not use S ducts, each designer uses what they think is the best solution.

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X-32 never made it pass being a technology demonstrator either.

MiG-29 said:

PAKFA might have some performance degradation it is possible, however it reduces mass and weight thus this allows for a lower fuselage weight than S-37 Berkut.

However S ducting increases weight and in order to reduce it the short and curved S duct also degrades performance.

Which one is better is up to the designer`s parameters.

For Sukhoi S ducts are not worthed on PAKFA because they wanted a lighter and smaller fifth generation

Which system is better is only tested and proven in the battlefield, history will tell perhaps in the future which system is better.

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Sukhoi went with straight inlets as this is found on the Su-27 and is the simplest to design. Moreover, the PAKFA took another piece of technology called variable intake ramp from the Su-27, which is extremely heavy. This weight has to be cut down from other parts of the PAKFA, leading to structural problems in the first prototype. Simply put, Sukhoi started with the Su-27 and applied existing technologies in the design of PAKFA. This indicates Sukhoi does not have the ability or resources to solve new challenges, such as those posed by something sophisticated like an S-duct.

It is not impossible to have a short serpentine inlet that has high performance, but as you pointed out very difficult. This is why the ability to design such an inlet is indication of a country's strength in aerospace technologies.

t2contra said:

The idea that innovation is determined by the political system of the country is an idea born in west which stubborn tries to denigrate the commie system. Westerners and some western oriented asians took to it as the bible of truth. China, since the start of its civilization, never had democracy, yet was able to invent many things. Joseph Needham documented them. Innovation arises out of necessity, to tackle a solution. In the west, where consumerism is more advanced, there are always new challenges, how to make the skateboard ride better, how to make my portable device more nimble, etc. China is now happily churning all these products for the world and there is really no urgent need to innovate to make a decent living. For China to be as innovative as the west, its standard of living has to rise. Even if there is no big prizes, like a Nobel, people will still innovate, so long as they are not penalized for their efforts.

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Point taken

Equation said:

Do you have solid evidence to back your claim, regarding your claim "never been tested in reality..."? No...I thought so. Also have you ever seen the inside of the DF-21D to compare it to the Pershing? No...I thought so. Like I said before the Pershing couldn't even match the DF-21D in speed and guidance system during rentry of the atmosphere flight.

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Right back at you: Do you have any evidence that DF-21D has been tested against a target like it was designed for? And please check up on the operational profile of the Pershing before you make another foolish and uninformed stated like "...Pershing couldn't even match the DF-21D in speed and guidance system during rentry of the atmosphere flight...."

".....The G&CC contained an inertial guidance system that could guide the missile on-target in a purely ballistic mode as a back-up. The primary guidance system was a Goodyear Aerospace active radar guidance system. Using radar maps of the target area, the Pershing II had a reported accuracy of about 30 metres (100 ft) circular error probable.[according to whom?]

The reentry vehicle (RV) was structurally and functionally divided into three sections: the radar section (RS), the warhead section (WHS), and the guidance and control adapter (G&C) section. Quick access connectors made the all three of the RV sections replaceable at the launching site.

The radar section consisted of the radar unit with the antenna enclosed in an ablative radome. The function of the radar unit was to transmit radio waves to the target area, to receive altitude and video information in return, and to send the detected video and altitude data to the digital correlator unit (DCU) located in the G&C section.

From:

That terminal radar system sounds exactly what the DF-21D is trying to do with its guidance trying to hit a carrier doesn't it? Now do you understand why I say that the father of the DF-21D is the Pershing 2?

AssassinsMace said:

Having a discusssion with the likes of Mig-29 and NikeX is pointless. They are the human analog version of a denial of service attack. All they're here to do is flood threads with repetitive, digressive, irrelevent posts.

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Funny how you cannot refute most of what is said with any solid technical information. All I ask is back up you rebuttals with real information. Do that and I will be the first to admit you are right on a point.

Refrain from using emotion and give us facts

J-XX said:

how in the world has NikeX not been banned yet?

the guy has completely ruined every single thread and mods have done nothing.

well if he can troll every thread, then we will all start to troll, it sets a precendent.

if its good for him, its good for all of us.

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I will ban myself if you prove I am in error or am launching personal attacks on members of this board. Otherwise I will continue to try and provide factual information related to Chinese defense subjects to the best of my ability

Providing factual information is something I appreciate. With your contribution in addition to Mig-29, I've googled a lot of different military related topics. I want to comment however that providing facts is one thing, and shoving it down our throats is another.

As informative as Mig-29 is, I've had to put him on my Ignore list as a result of his consistent and repetitive off-topic postings. I heed you not to do the same.