J-20... The New Generation Fighter II

[Martian]

Your idle musing is contradicted by expert Paul Bevilaqua in the prior post

Weapon bay may be small as seen on F22...

Bill Sweetnam latest article He said a lot of good thing about Canard

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I remember talking this over with Paul Bevilaqua at the 1993 Powered Lift Conference in Palo Alto. If I remember correctly, one reason for the canard delta was that it was good for the cross-sectional area distribution (area ruling) and hence transonic drag.

The challenge was that the shaft-driven lift fan design inevitably had a big cross-section peak well forward, where the inlets wrapped around the fan bay (it needed a large-diameter fan and lots of airflow to work). A canard delta compensated for that by moving the thickest part of the wing as far back as possible.

Somehow I don't think we're going to see a J-20 with a lift fan. However, don't be surprised if the weapons bays turn out to be more capacious (and versatile) than on other designs. It looks like the idea of the canard configuration is to get a large-volume mid-body section through the transonic zone and into supersonic flight with minimal fuss, bother and expenditure of fuel.

Bevilaqua's paper on the origins of the F-35 design cites risk as the reason for the reversion to a quad-tail design for the JSF competition in 1996 - and at the time both Eurofighter and Saab were dealing with unexpected issues in this area.

However, another Lockheed Martin engineer explained that the final JSF planform design was more flexible in terms of being enlarged to meet Navy requirements (given that LO constraints and commonality mandated the same sweep angle for all versions).

That may have been the biggest non-STOVL driver to affect the design, although canards were definitely not popular in the US in the mid-1990s - and I suspect that fitting the canard design on to an LHA elevator might have been a challenge.

Bajrangbal, it would help if you read the post prior to your own that contains the opinion of an expert, Paul Bevilaqua. He specifically said (or told Aviation Week's Bill Sweetman) that the J-20's "weapons bays [were designed] to be more capacious (and versatile) than on other designs."

 

[latenlazy]

Naturalized Yes, security background check definitely. I work in dod for long time, and i don't see too many naturalized chinese in all the company i work for, especially if there are 1st gen. Also Almost all naturalized chinese has a degree in US, higher education in china is still lack behind compare to US.

In order to work for defense, 1st you have to have a degree that the company recognize, which mean you basically has to have a degree from a western university(1 yr master, 4-5yr phd), after that You apply H1B, and if you lucky you get a job and they support your green card. Then you get green card(few years), then US citizenship(few more years), by the time you get the US citizenship you already live in US for more than 10yrs+. Only then you are able to apply for sensitive, defense related job. So most experience you get IS from working under US company. I have never heard someone who came from china with work experenice got hired immediately to a DoD job. So NO, the chinese who are here working on military and sensitive stuff got their experence within US. Depend on what part of NASA, there are different level of security.

US immigration and naturalization policy was not as strict in the 90s, and the most highly educated applicants usually got bumped to the top of the queue, and most naturalized individuals working in US defence firms are of that generation of immigrants. Furthermore, a lot of Chinese immigrants go through Canada first, where the naturalization process is much faster, and then obtain a fast track route to permanent residence status and naturalization in the US.

 

[challenge]

notice something, that J-20 like F-22 has no intruding antenna blade,both aircraft uses "smart Skin".
there's old article in the late 90's about the R &D on "smart skin' in xian aircraft, according to article it generate a lot of heat,the article I believed appear 10 years ago.
and during the 2004 zhuhai airshow, poster featuring fly by light flight control system .
J-10B like J-20 may have adapted fly by light control system.

 

[challenge]

giving the price tag of the aircraft, only few number will produced,there's alternative solution was equivalent of "Silent flanker" with weapon store in redesign central fuselage. and single engine and smaller F-35 type J-20.

 

[Asymptote]

what's the name of the guy? how old is he? where was he born? how long did he work on B-2?
I can make an another article for this:
In fact, some guy from Hawaii who was an Engineer who worked on the B-2 sold some secrets to the Russian governments, you can have almost no doubt that some of that knowledge was incorporated into the T-50 demonstrator.

The indian guy's name is Noshir Gowadia. He joined Northrop in November 1968, and continued to work there until April 1986. As a design engineer, Gowadia was reportedly one of the principal designers of the B-2 Spirit stealth bomber, who conceived and conceptually designed the B-2 Bomber's entire propulsion system and billed himself as the "father of the technology that protects the B-2 stealth bomber from heat-seeking missiles." He apparently gave a lot of "lectures" in China, and he was sent to jail for that.


Another interesting bit about this is as some posters have talk about who can work in the US defence industry,
Noshir Gowadia was born Bombay (Mumbai), Most likely to have been educated in India and didn't immigrate to US until well after college. So this is very interesting, as it shows you CAN work in US defense industry even if you are not born in US. It is possible after Gowadia's case that they tighten up that rule and now only allow 2nd or 3rd generation immigrants to work in defense industry.

 

[Asymptote]

Yes actually, the F-22 is really the only fully indigenous Fighter programs out there. PAK-FA still uses a bit of foreign tech while the J-XX demonstrator uses a bit more than the PAK-FA.

Actually, the whole concept of "radar stealth" was "stolen" (or copy or plagiarize.. whatever you call it) by American from the Russian.

The original concept / theorem was developed by a Russian mathematician/physicist named Petr Yakovlevich Ufimtsev.

From wiki:
"Petr Yakovlevich Ufimtsev (Russian: Пётр Я́ковлевич Уфи́мцев) (born 1931 in Altai Krai) is a Soviet/Russian physicist and mathematician, considered the seminal force behind modern stealth aircraft technology. In the 1960s he began developing equations for predicting the reflection of electromagnetic waves from simple two-dimensional shapes.

Much of Ufimtsev's work was translated into English, and in the 1970s American Lockheed engineers began to expand upon some of his theories to create the concept of aircraft with reduced radar signatures.[1] Northrop made extensive use of Ufimtsev's work in developing the B-2 bomber."

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So, no, American didn't completely indigneously develop the stealth aircraft. It stole MANY ideas and designs from foreign origins (with foreign help as well - see Noshir Gowadia case). And these are just known facts, there are many more we would not know until the whole project is completely unclassified one day (in maybe 200 years time )

 

[Asymptote]

Yes, I am VERY familiar with the process you talk about. My parents went through the exact process (I piggy-backed). Yes, most of these people get their post-graduate education in the US, but don't expect them to completely throw away what they had learn in their home country. I am not particularly talking about the exact knowledge/theories we learn in school, but things like the way of thinking, culture, etc. This kind of stuff sticks with you all your life. Just try to argue with my dad about Confucius (although he's been in the States for over 30 years), you'll know what I'm talking about. And developing new technology/systems is a creative process that depends on many things in addition to actual technical knowledge/theories. A lot of times, your cultural up-bringing and way of thinking play a big part.

Additionally, I'm NOT talking about particularly Chinese immigrants. My comments were more aimed at your comments "US technology is purely domestic and has not foreign influence". So I was trying to show you that the US also needs foreign help and many its high tech systems have foreign influence since many of their designers have heavy foreign influence. Although some of my examples were Chinese, I also listed many examples about how European immigrants works in the DoD industry.

So my point is US DoD industry is also influenced by foreigners. If not by Chinese, it could be by Indians, British or German or Russian. The US is too big a melting pot to exclusively conclusively say that its technology has no foreign influence.

I don't know which part of DoD industry you work in, but where I can see DoD industry or institutes are full of first general immigrants. When I was in grad school, I used to collaborate with US Army on projects (about battlefield injuries, especially spinal core injuries since my field of study used to be inflammation). I know that many colleagues I've worked with are first generation immigrants. Most of these people work in biological weapon field (anthrax stuff...).

As a matter of fact, I know people who join the military in the States TO OBTAIN A GREEN CARD. So even the US military has foreigners (with actual foreign citizenship).

You know a funny thing? I know an IRANIAN guy who is working on a DARPA research project on robots. Who knows maybe American are making Terminators secretly but it is actually developed by IRANIAN! HAHA!!

The fact remains, while you need to have clearance to work in defense industry, many college/university projects are funded by DARPA/US DOD at conceptual level. And I am pretty sure you don't need clearance to do those.

 

[challenge]

what is main topic again? J-20 or the US immigration policy????

 

[bd popeye]

So, no, American didn't completely indigneously develop the stealth aircraft. It stole MANY ideas and designs from foreign origins (with foreign help as well - see Noshir Gowadia case). And these are just known facts, there are many more we would not know until the whole project is completely unclassified one day (in maybe 200 years time )

Not completely true. The book the man wrote was readily available for anyone to read. So nothing was stolen. The question is..why did not the Soviets/Russians develop a stealth aircraft?

 

[Red Moon]

Not completely true. The book the man wrote was readily available for anyone to read. So nothing was stolen. The question is..why did not the Soviets/Russians develop a stealth aircraft?

His use of the verb "to steal" is just kind of a rejoinder to IronsightSniper, who said, or implied the same thing in reverse.

As to the Russians... the economy!