J-20... The New Generation Fighter II


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MiG-29

Banned Idiot
No. Giving the dictionary definition of drag does not remove the influence of drag coefficient. You are cherry picking the wing area parameter out of the equation and try to portrait it as the sole determinator of drag. You are also trying to portrait fuselage area as wing area when the equation specifies that area is the referenced wing area. Your argument is invalid as a result.
I gave you the equation for drag and definition but you still can not understand that is not my fault, but if you answer that way at an univertsity test you will flunk the test.
 

MiG-29

Banned Idiot
On aircraft such as the Eurofighter where canards move in sync, you would be correct. However, you are incorrect when you generalize this to argue that canards only provide pitch control. Canards can move independently and provide roll control just as tail planes can. Canards that move independently can also provided limited yaw control, due the ability to control strength of vortices generated by the canards.
show me a video and i can prove you the J-10 only uses the canards as pitch control, in this video the J-10 does some rolls it never moves differentially the canards because it uses the wing trailing flaps as roll control and keeps the canards as lift devices.
so far your J-10 shows you are incorrect the J-10 shows you are wrong
[video=youtube;iA7Pwek0nEc]http://www.youtube.com/watch?v=iA7Pwek0nEc[/video]
 

Engineer

Major
Now compare the J-20 to the Rafale

The first think it will strike you is the wing of the Rafale is positioned further forward from the engine nozzles and the main landing gear is farther back from the wing root and leading edge.
This shows easily tha all Eurocanards are unstable longitudinaly and the J-20 is closer to the Viggen in configuration
Similar to your previous argument regarding the stability of the J-20, you cannot judge the position of aerodynamic center based on the position of the wings. The aircraft's aerodynamic center is not the same as the aerodynamic center of the wings. When discussing stability, it is the former that counts.

the Rafale also has LERXes but its canards are closer to the wing and above it, this means their vortices re-energize better the wing (if you disagree you can read technical documentation about canards and see all fighters J-10, Gripen Eurofighter, Rafale, MiG1.44 have the same configuration)
Separation distance between canards and the wings is not the same as separation distance between aerodynamic center and the center-of-gravity. Whether vortices by canards can better re-energize flow above the wings is irrelevent when we talk about stability, since stability is not agility.

the conclusion is the J-20 is more a striker than a fighter and only with advanced avionics and missiles will be able to fight, this is not to minimize or belittle it, it is a tornado adv type fighter with modern stealth
False. The designation "J" indicates J-20 is a fighter. It's as simple as that.

in this picture you can see the vortex formation on the Rafale and you can see its LERXes and inlet forebody do create Vortices increasing AoA handling
J-20's chins, canards, and LERXs also create vortices to increase lift at high AoA.

however this proves the Rafale has higher levels of relaxed stability and has a better canard position
No. This proofs nothing with regards to stability, since you do not have knowledge about the position of aerodynamic center with respects to the center-of-gravity.

question for you where is better to put a canard see these three aircraft and tell me where is the canard better positioned?
Canards are placed where they are because the aircraft's designers deem that location is the good position. I would not challenge their decision.

Now answer and tell me which design has a delta wing and canard more of a fighter the J-10 or the J-20, the Rafale or the J-20?
J-20 is a fighter.
 

johnqh

Junior Member
If you asked me about China's 4G fighter one year ago, I would have said "no way"!

If you asked me about China's airborne PESA or AESA radars one year ago, I would have said "no way"!

If you ask me right now about WS-15, I say "no way".

.....but who knows......
 

Engineer

Major
I gave you the equation for drag and definition but you still can not understand that is not my fault, but if you answer that way at an univertsity test you will flunk the test.
You gave the equation which states drag is a function of air density, drag coefficent, air velocity, and wing reference area. You cherry picked wing reference area to try to argue area being the sole determining factor on drag, and try to draw inference to conclude J-20 having higher drag by misrepresenting fuselage area as wing reference area. You sir, will be the one who will flunk the test.
 
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Engineer

Major
show me a video and i can prove you the J-10 only uses the canards as pitch control, in this video the J-10 does some rolls it never moves differentially the canards because it uses the wing trailing flaps as roll control and keeps the canards as lift devices.
so far your J-10 shows you are incorrect the J-10 shows you are wrong
False. J-10's canards can deflect independently, this is a fact. Thus, the canards contribute to roll control, as well as limited yaw control. Your inability to distinguish small deflection between the canards during the aircraft's flight is not a proof that the canards cannot deflect independently, nor is it proof that such canards do not provide roll control authority.
 

siegecrossbow

Brigadier
Staff member
Super Moderator
show me a video and i can prove you the J-10 only uses the canards as pitch control, in this video the J-10 does some rolls it never moves differentially the canards because it uses the wing trailing flaps as roll control and keeps the canards as lift devices.
so far your J-10 shows you are incorrect the J-10 shows you are wrong
[video=youtube;iA7Pwek0nEc]http://www.youtube.com/watch?v=iA7Pwek0nEc[/video]
No offense but just because the J-10 didn't use the canards for roll in one video means that it can't use it for roll, ever? What kind of logic is that?
 

siegecrossbow

Brigadier
Staff member
Super Moderator
If you asked me about China's 4G fighter one year ago, I would have said "no way"!

If you asked me about China's airborne PESA or AESA radars one year ago, I would have said "no way"!

If you ask me right now about WS-15, I say "no way".

.....but who knows......
That is an important point. Too many analysts use Western time frames to judge the developmental speed of Chinese military projects.
 

Bltizo

Lieutenant General
Staff member
Super Moderator
Registered Member
If you asked me about China's 4G fighter one year ago, I would have said "no way"!

If you asked me about China's airborne PESA or AESA radars one year ago, I would have said "no way"!

If you ask me right now about WS-15, I say "no way".

.....but who knows......
I feel that will be a recurring theme in this decade as the aerospace and general arms industry starts to reap the rewards of years of investment and the goal of indigenization.

Personally I'm looking forward to the Y-20 and SAC's X-45/47 like UCAV, hopefully by 2013.
 
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