J-20 5th Gen Fighter Thread VI

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b787

Captain
I didn't know fighters were supposed to be optimized for low speed :rolleyes:. There is a reason why pointing to one lift coefficient value tells us nothing about performance. You need to look at the *whole* lift curve.
My avatar was, the wing swept is and always will be a reference at what speed an aircraft operates, J-20 is intended to cruise at higher speeds and the canards are only used to enhance its low speed handling, but yes they are intended for low transonic speeds in previous generations, 5th generation are designed as aircraft to cruise at Mach speeds of 1.3-1.8 and large wings and TVC nozzles are used for increase STOL and maneuverability. :D

Did you understand reference area is to consider aircraft have a center of gravity and symmetry longitudinal line? thus the wing span is used to consider its effective area of application of 2 wings but longer wing span increases gliding capability thus gliders use it.

Any way this is highly off topic so i will leave it here :);)
 
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latenlazy

Brigadier
You do not know what you are saying at all, one thing is exposed wing are and another reference wing area which uses the longitudinal symmetry reference line

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For starters the Flankers like the F-14 has wider wing span why? simply because the engines are widely separated, thus the reference area has wider wing span thus more area and the Su-27 like F-14 has the pancake area which also generates lift.

Same is the F-14, you are dreaming the F-14 at lower speeds has higher lift than J-20, it has much wider area due to longer wing span thus using reference area the Tomcat is designed for lower speeds and will get much higher lift at landing approaching speeds.
F-14 also increases camber when it sweeps to lower angles thus it generates more lift.
You can see easily Deltas are not good naval fighters, but good interceptors

The exposed wing of the J-20 is not big, is the wetted area of the wing the real wing, and is not part of the fuselage, it is the actual wing.

J-20 is designed for higher cruising speeds than Flanker, you can see Su-57 also has more swept wings, but F-14, Su-27 and Su-57 have widely separated engines, F-14 did not use canards at landing or take off but Su-27 needed them during approach the landing speeds thus they made the Su-33.

J-20 uses bigger canards than Su-33, however Deltas lost lift in wing tip vortex generation.


This affects lift when they turn so deltas use canards to recover lift using the vortex of the canard to reinforce lift in the main wing.
Su-35 has high yield engines lower swept and TVC nozzles, the fighter will be superb at sustained turn rates, but is not that good as Rafale as instantaneous turn rates due to higher wing loading.


J-20 uses fuselage lift and the canards to compensate for the small wetted area and smaller wing span, with TVC will achieve STOL capability improving landing and take off speeds
The point you seem to be walking around and avoiding is that 1) Exposed wing area by itself tells us *nothing* about the lifting properties of a wing or design. The entire body of the aircraft is one cohesive lifting system. You can't know a thing about the aircraft's flight properties by singling out one feature and component. You have to look at the airflow interactions happening along the *whole* airframe. *This is why we need to know the lift coefficient curve* in order to make *any* assessment about the J-20's flight characteristics and how it compares to other designs. This is not as essential a point for commercial airplanes because commercial airplanes aren't complex blended shapes. They're designed around large wings and a narrow cylindrical tube. 2) Wing loading is calculated with reference wing area, *not* exposed wing area, because the whole point of wing loading is to figure out the average mass per area that is being worked on by the lifting force on the whole plane. You can keep trying to talk yourself into circles and knots and that basic point *doesn't change*. Wing area as a parameter for calculating total lift refers to reference wing area, not exposed wing area. If you took an aerodynamics course and answered a question using exposed wing area for the basic lift equation you would have gotten the answer wrong.
 

latenlazy

Brigadier
My avatar was, the wing swept is and always will be a reference at what speed an aircraft operates, J-20 is intended to cruise at higher speeds and the canards are only used to enhance its low speed handling, but yes they are intended for low transonic speeds in previous generations, 5th generation are designed as aircraft to cruise at Mach speeds of 1.3-1.8 and large wings and TVC nozzles are used for increase STOL and maneuverability. :D

Did you understand reference area is to consider the wings have a center of gravity and symmetry longitudinal line? thus the wing span is used to consider its effective area of application but longer wing span increases gliding capability thus gliders use it.

Any way this is highly of topic so i will leave it :);)
No fighter planes are optimized for cruising at Mach 0.5 if that's what you mean. That doesn't tell us anything about actual performance and capability though. The wing *area*, not the wing *span* is used to consider effective area of application. Area of application is two dimensional (planar), not one dimensional. Lifting forces act on an entire surface, not a line.

Anyways you're trying to shift the goal post to hide the fact that you made a bs claim and you aren't able to defend it.
 
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vesicles

Colonel
My avatar was, the wing swept is and always will be a reference at what speed an aircraft operates, J-20 is intended to cruise at higher speeds and the canards are only used to enhance its low speed handling, but yes they are intended for low transonic speeds in previous generations, 5th generation are designed as aircraft to cruise at Mach speeds of 1.3-1.8 and large wings and TVC nozzles are used for increase STOL and maneuverability. :D

Did you understand reference area is to consider aircraft have a center of gravity and symmetry longitudinal line? thus the wing span is used to consider its effective area of application of 2 wings but longer wing span increases gliding capability thus gliders use it.

Any way this is highly off topic so i will leave it here :);)

Your whole point is predicated on the assumption that the J-20 has smaller wing area. You haven't shown the numbers to back up any of your points. You need to show evidence for any of your assertions.
 

b787

Captain
Your whole point is predicated on the assumption that the J-20 has smaller wing area. You haven't shown the numbers to back up any of your points. You need to show evidence for any of your assertions.
J-20`s wetted area of exposed wing

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The article that originally was discussed said " J-20 has a 25% smaller wing than F-22"
 
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