J-20 5th Gen Fighter Thread VI

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taxiya

Brigadier
Registered Member
Ughhh, The abstract Klon posted is a description of RAM or Radar Absorbing Material not the recent Buzz word Meta-material.
Meta-material is a 3 Dimensional shape that does not occur in nature which has special properties.

As for your posting;


This is just techno gibberish.
Whether natural occurring structure or meta-material structure it all has a natural resonating frequency. With out some kind of outside source of energy you can't change frequency of a wave which you are suggesting.
The closest thing you suggest is Smart Skin technology that Japan is doing research in which they vibrate the outer skin of a plane with plasma to emit or cancel out low energy radar just like sound cancellation system you see in ear phones these days.

What LM did is in the same principle as metamaterial without using the name "metamaterial". Metamaterial is a little bit a buzz word. LM's approach is forming the micro structure by laying wires layer by layer in composite. What this metamaterial is another approach in fabrication, printing like PCB. This new approach can do what LM can not, that is the structure is more sophisticated. It is also easier to realize with high guarantee of accuracy in terms of the pattern. I'd say their difference is similar to handmade RR car vs. production line made Ford, but they are all cards going from A to B.

The most important difference between LM's approach and the metamaterial from RAM is that, RAM (in the scense of F-22) does not have the pattern of wires which act like wave guide (on several millimeter lever). RAM relies on the atom/Christal structure on chemical level (much smaller).

Did I say metamaterial change frequency? I don't remember. Did I say metamaterial can not be connected to external ernegy source (like electrical circuitry of the aircraft)? I did not say.

Please don't attack a ghost.

What Japan is doing, I will not comment until there is something more concrete to be studied.
 
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AleDucat

New Member
Registered Member
Hi, is there any info concerning J-20’s internal gun? As long as I know, it should be mounted over port intake covered with a front door, but anyone here has read/heard about caliber or gun type?
 

plawolf

Lieutenant General
There is no indication that the current version of J-20 has a gun.

That door is the indication. The external access panel design on the prototype was also an obvious give away that what is under that door is a gun and not the APU.

I find it hard to fathom how people could honestly conclude that just because the external panneling was changed on the production models, to give better RCS performance, that they suddenly changed the internal structure also to take out the gun.

The alternative theory that the door is for the APU does not pass the simple logic test of why the door needs to be where it is.

Just look at where the APU on the F22. That is designed so that the door is deliverably hidden form the front, to eliminate another possible source of RCS spike.

The F35 is in a different league since it is designed primarily for AG, and is a much smaller platform, meaning the designers had much less room to work with; and also had to make additional compromises to account for the 3 versions.

Point is the J20 is a much bigger aircraft, and is designed primarily, maybe even exclusively, for AA. That means frontal aspect stealth matters the most for it; and it has plenty of real estate to play around to mount the APU intake somewhere where it is not even a possibility that it could cause a RCS spike.

With the J20 designed form the offset to counter the F22, it would be an unfathomable omission to not include a gun when a F22-J20 encounter is more likely than not to go into, and be decided in, WVR.
 

taxiya

Brigadier
Registered Member
It just comes to me that the bump is covered by different layers of material, there is the green in this photo. We have also seen it covered by copper yellow layer in place of the green. Then there is the photo showing it being covered by the same yellow tone of the rest of the fuselage. It would be interesting to know the order of applying the layers.
 

latenlazy

Brigadier
It just comes to me that the bump is covered by different layers of material, there is the green in this photo. We have also seen it covered by copper yellow layer in place of the green. Then there is the photo showing it being covered by the same yellow tone of the rest of the fuselage. It would be interesting to know the order of applying the layers.
Also possible that they are testing different materials.
 
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