J-20 5th Gen Fighter Thread V

[siegecrossbow]

let me laugh about the non sense you wrote MiG-25 has lower TWR and higher wing loading than the F-15, when you get higher thrust to weight ratio F-15 near 1:1.3, MiG-25 1:0.7 you can see the MiG-25 was not a dogfighter.

That didn't stop early Western analysts from thinking that it was. MIG-25 had large wings and control surfaces and there was speculation that it consisted primarily of titanium instead of steel. Goes to show that it is dangerous to draw conclusions when you don't have all the necessary data.

 

[b787]

Why do you need more lift at higher AOA if you don't intend to maneuver? Many of the newer bomber/interceptor designs place their intakes on the back precisely because there isn't a requirement for high AOA flight.

As for the actual wing loading... We don't know precisely how much the J-20 weighs. Your argument is based on conjecture.

higher lift at higher AoA means a higher instantaneous turn rate, most deltas get a limit in lift, so you get aids like canards, LEXs or LEVCONs to fix that and TVC nozzles are another type of aid.

the wing loading tell you how high is that lift

 

[siegecrossbow]

higher lift at higher AoA means a higher instantaneous turn rate, most deltas get a limit in lift, so you get aids like canards, LEXs or LEVCONs to fix that and TVC nozzles are another type of aid.

the wing loading tell you how high is that lift

That's a very good point. Why do you need a higher instantaneous turn rate if you don't need to maneuver? Wouldn't it be better to invest in pure/compound delta with larger area and even smaller aspect ratio? If the goal is fast interdiction, that would make more sense wouldn't it?

Just look at Boeing's designs (with known requirements).

Please, Log in or Register to view URLs content!

We see a minimal control surfaces, no visible LERX/strakes, and in the case of the former image the intakes are located on the back of the plane.

Also checkout the design for FB-22 and F-16XL, both optimized for bombing.

 

[dingyibvs]

Oooh, I just watched the whole thing. When asked how J-20 compares to American stealth fighters, he said that J-20 is more maneuverable than F-22 and it's radar capability is on par with F-22, F-35. It possesses BVR capabilities on par with F-22. However, it's supercruise capability lags behind the Raptor due to an insufficiently powerful engines at this phase. He also notes that J-20 is still immature and still being tested/improved even as LRIP is commences.

I think he said more aerodynamic, not more maneuverable than the F-22.

 

[b787]

That's a very good point. Why do you need a higher instantaneous turn rate if you don't need to maneuver? Wouldn't it be better to invest in pure/compound delta with larger area and even smaller aspect ratio? If the goal is fast interdiction, that would make more sense wouldn't it?

Just look at Boeing's designs (with known requirements).

Please, Log in or Register to view URLs content!

We see a minimal control surfaces, no visible LERX/strakes, and in the case of the former image the intakes are located on the back of the plane.

Also checkout the design for FB-22 and F-16XL, both optimized for bombing.

come on please Mirage 2000, Mirage III or even LCA are air superiority fighters, a canard or an aft tail are used because it frees the trailing edge flaps for lift, letting the aft tail or canard as pitch or roll control, the Mirage III could beat the F-4 or MiG-21, and sames goes for the Mirage 2000, it beat the F-16 in some flight regimes, in fact the only F--16 lost to enemy fighters acknowledged in air to air combat was to a Mirage 2000.

With TVC nozzles you get even more freedom to the tailess and with LEVCONs you can get a pretty agile fighter, the 6th generation fighter is going to be like that, and that potentially could kill j-20 and PAKFA with higher stealth than F-22

 

[manqiangrexue]

let me laugh about the non sense you wrote MiG-25 has lower TWR and higher wing loading than the F-15, when you get higher thrust to weight ratio F-15 near 1:1.3, MiG-25 1:0.7 you can see the MiG-25 was not a dogfighter, F-22 supercruises because it has excess power and very low SFC, J-20 without being able to supercruise is a joke it will out manuevre the F-22, specially f the F-22 uses TVC nozzles on a 1:1 combat, the only chance for the J-20 will be have a better HMS and a very advance missile like AIM-9X and the avionics of F-35

The only thing you should be laughing about is when people say cross-section and you think length and when people say fighter engine, you think Brazilian missile engine. And your English, you can laugh about that too. He did not say J-20 cannot supercruise; he says its supercruise ability is less than the F-22. You are funny; you really think you know all the answers here, don't you? You think you can sit down with a piece of paper and pencil and you can figure out what classified fighter designs can do. And that's what everyone here is laughing about.

 

[vesicles]

I need some help understanding why the USAF and USN F-35's don't have TVC any more. The F-22 is such a success. It's still the benchmark for what a 5th gen fighter should be like. One would think they would want to emulate the F-22 design as much as possible. Yet, they decided not to include the TVC in two of the 3 variants of the F-35.

One would expect that they would want to keep the TVC in all 3 variants, just from the standpoint of simplifying the design. And simplifying design and maintenence was a big factor in deciding to use a single frame for all missions. Yet, they designed a completely different engine for B. This seems to defeat the purpose of using the same airframe for all variants.

There must be some kind of penalty associated with the TVC that they specifically design different engines for different variants.

The fact that only the F-35B has the TVC actually suggests that they simply had no choice because of what the USMC wants and were "forced" to put the TVC in...

If you also look at the missions in different branches, you will see an intriguing trend. The USAF and USN F-35's, which will most likely face off with opponent fighters in A2A combats and need to be maneuverable, don't have TVC. The USMC F-35, which will be the least likely to engage in A2A fights, got a TVC. So what is the purpose of the TVC? Most likely not maneuverability?

Another question. Can the F-35B actually use its TVC in fight, or just during take off and landing?

 

[manqiangrexue]

I think he said more aerodynamic, not more maneuverable than the F-22.

He said "ji(1) dong(4) xing(4) neng(4)" which means ability to move vigorously/dynamically. I take that as maneuverability.

 

[SamuraiBlue]

I need some help understanding why the USAF and USN F-35's don't have TVC any more. The F-22 is such a success. It's still the benchmark for what a 5th gen fighter should be like. One would think they would want to emulate the F-22 design as much as possible. Yet, they decided not to include the TVC in two of the 3 variants of the F-35.

I believe they are concerned of the one engine problem. TVC is based on mechanical moving components and if it fail it means the plane would not be able to maintain flight.
With the F-22 they can always cut off one engine and maintain the other TVC into neutral and head back to base.
Basically they did not want to add another layer of possibility that may fail in combat which could lead to fatality of the pilot and mission.

 

[Inst]

The Russian experience with canards was with a retrofit, as opposed to a specialized design. It did not offer enough advantages and the Su-35 is canardless, utilizing TVC instead. With the J-10, J-20, and the Eurocanards, the aircraft were designed to maximize canard advantages and so thus are different from the Russian experience with the Su-30 and Su-33. Naturally, the Russians then moved to LEVCONs, but the LEVCON has trade-offs vs conventional canards. Likewise, LEVCONs have trade-offs compared to LERXes and chines.