J-20... The New Generation Fighter III

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MiG-29

Banned Idiot
Popeye agreed to new thread. All future aerodynamics related discussion should go here:

http://www.sinodefenceforum.com/air-force/aerodynamics-thread-5907.html#post181146
hey i have a question, and this is what annoys me, many of the news reports have aerodynamic points, you yourself had an aerodynamic question due to a video and a picture, then when is the thread moving to off topic?

if i answered you your question, then both of us are off topic?
then it means your question should have been sent to that thread, not even asked here so this is what annoys me, why only leave this thread for pure news, and making separate threads for each news, because this is what annoys me, J-20 is an airplane, its aerodynamics, so if you ask a question like you did comes blitzo if i answer claiming foul, then you should not have asked the question in the first place, and i do not think is fair if some one else answers you the same question call him on topic but if i answer you then is off topic.

And that is what annoys me

---------- Post added at 11:04 PM ---------- Previous post was at 10:53 PM ----------

Popeye agreed to new thread. All future aerodynamics related discussion should go here:

http://www.sinodefenceforum.com/air-force/aerodynamics-thread-5907.html#post181146

can i open a separete thread about doctor song`s paper aerodynamics?
 

Air Force Brat

Brigadier
Super Moderator
hey i have a question, and this is what annoys me, many of the news reports have aerodynamic points, you yourself had an aerodynamic question due to a video and a picture, then when is the thread moving to off topic?

if i answered you your question, then both of us are off topic?
then it means your question should have been sent to that thread, not even asked here so this is what annoys me, why only leave this thread for pure news, and making separate threads for each news, because this is what annoys me, J-20 is an airplane, its aerodynamics, so if you ask a question like you did comes blitzo if i answer claiming foul, then you should not have asked the question in the first place, and i do not think is fair if some one else answers you the same question call him on topic but if i answer you then is off topic.

And that is what annoys me

Mig popeye suggested that you start a T-50 thread, like you I am more interested in the turn and burn stuff, but not everyone on this thread shares our interest, in fairness to you, a lot of us are obviously interested in this, and we did kind of draw you into this. So in the interest of love peace and real airplane talk lets try it out. Seige and Player, i.e. any of you guys that had input into a great forum type discussion, I hope you'll try to join us on that thread, to be honest this was the best discussion I have ever been involved in, but my apologies to any we might have offended by hogging the J-20 thread. "Break Now Jester" Brat OUT
 

Player99

Junior Member
View attachment 6259

This one. The canard were deflected downward which means the pilot was pushing the nose downward during a turning maneuver. Not logical at all.

To my memory, all the photos of J-20 doing a turn show the same pattern, for which i.e. has an explanation, and Mig-29 seems to have one, too. To my layman's eye, I just don't see any control surfaces doing apparently enough to lift the nose in order for the turn to happen.

i.e. says it's the lift that makes the plane turn. Fine, but that lift has to be more on the nose end and can't be equal on the whole bottom of the plane, or it would only push the plane higher and higher, instead of making it run in circles, wouldn't it?

Or, are some of the control surfaces pushing down the tail during a turn? Otherwise, and again to my layman's reasoning, the plane would have gone off at a tangent instead of turning circles.
 
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paintgun

Senior Member
hey i have a question, and this is what annoys me, many of the news reports have aerodynamic points, you yourself had an aerodynamic question due to a video and a picture, then when is the thread moving to off topic?

if i answered you your question, then both of us are off topic?
then it means your question should have been sent to that thread, not even asked here so this is what annoys me, why only leave this thread for pure news, and making separate threads for each news, because this is what annoys me, J-20 is an airplane, its aerodynamics, so if you ask a question like you did comes blitzo if i answer claiming foul, then you should not have asked the question in the first place, and i do not think is fair if some one else answers you the same question call him on topic but if i answer you then is off topic.

And that is what annoys me

there are many people reading SDF, and not everyone into the aerodynamics stuff, there are some who logs flight, or wait for developments, often weeks in between logging into SDF, to find what? the thread clogged by off topic discussion
imagine this spread to other thread, and make someone miss a critical plane serial, they got to be pissed

people like siege and blitzo tries to stay on topic as possible, only commenting to very recent and pertinent image or development, you on the other hand paste a whole article, old ones even, and brings up comparison where it is unnecessary, also drop the big and bold fonts. we can read well you know, and if there is an important point don't worry we won't miss it

now the mod has created an aero thread for everyone, i suggest you use it well
 

kyanges

Junior Member
Good News and Bad News.

The good news is that the wingspan is about 13 meters. The bad news is that the J-20 is about 18.7 meters long, if you go by satellite photos and use the J-10 to compare, using the J-10 wingspan as a measuring stick. This results in 64.7m^2 wing area. On a 25k combat weight, this translates to a mediocre 386 kg / m^2. On a 30000 kg combat weight, this translates to a 463 m^2. Even if you add in the canards, a 70 m^2 on 30000 kg only gives you 428 kg / m^2.

Wing loading is pretty severe on this fighter. Hopefully the Rafale-lite config can cancel this out.

Wait... I know you said it's from satellite photos, but I'm curious specifically who calculated the 18.7 number. Yourself, or is it from somewhere else? A little while ago, I read in this thread that the daily airshow viewers set out 20-21 meters.

18.7 would make it shorter than the F-22 right? o_O . Is the J-20's body really that much of an optical illusion, or are the viewers in Chengdu right while the satellite image is just fuzzy...?
 

Blitzo

Lieutenant General
Staff member
Super Moderator
Registered Member
@mig, it's not a discrimination against you or anything, but let's be frank, past threads which you've contributed to (especially this one) have been diverted with pages and pages of aerodynamic posts by you and others. There was that (again I say, interesting) aerodynamics thread a few months back where there were dozens and dozens of pages of posts. Preferably they should be in a different thread rather than the main J-20 thread where members and visitors will likely be attracted to. Most will want to see pics and news and information tidbits about J-20 rather than long winded, multiple post spanning analysis and debates on aerodynamics.

Just sayin, imho.

And siege, lol not sure if you're reading the same thread I am, I think no one's taking anything personally :p

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@kyanges, yeah 18.7m is a bit short. Last year I remember calculating (based on J-20 vs truck whose dimensions we acquired) its length to some 20m. And even if we could calculate wing loading that doesn't translate exactly to the plane's real kinematics (the principle i learnt was that an aerodynamic feature doesn't immediately translate into an overall effect without taking into account other factors. And for the aerodynamics of an advanced 5th generation aircraft that should certainly be the case.)
 
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escobar

Brigadier
:confused:
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A China Air Force official has disclosed that the test flights of Chinese J-20 fighters have been carried out successfully and the aircrafts are expected to start serving in the near future.

Major General Wei Gang, also the former Minister of the Equipment Department of the People's Liberation Army (PLA) Air Force, told the media that "although not this year, it will be soon" for the J-20 fighter to begin service.

Wei also said that no matter whether they are 'home-made' or imported fighter jets, test flying is necessary and crucial.

The abovementioned remarks were made when Wei took part in the Fourth Plenary Meeting during the Fifth Session of the 11th National People's Congress (NPC) on Mar. 11.

The J-20 fighter aircraft, or Chengdu J-20, is known as the fourth-generation Chinese home-made stealth, twin-engine fighter aircraft. It has caused worldwide concern since its debut flight on Jan. 11 of last year in Chengdu.

After its debut, Guan Youfei, Deputy Director of the Foreign Affairs Office of China's Defense Ministry, declared that the development of China's military hardware "is not aimed at any other country or any specific target".

All weapons are developed to safeguard the country's sovereignty, national security and territorial integrity and they are tailored to the world’s latest military changes and weapon trends
 
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