Zhuhai Airshow 2022


SEAD

Junior Member
Registered Member
“Particular effectiveness for L band” needs to be quantified and contextualized. What does “particular effectiveness” mean? Can’t just mash up contexts between one claim about -30 dbsm and another claim about “particular effectiveness in L” willy nilly…
Sure. I just cannot find the raw report of 30dB but using another report to show what I want to show. You can forget 30dB anyway, after all 4dB is farrrrrr away from effective by any standard.
 

latenlazy

Brigadier
Sure. I just cannot find the raw report of 30dB but using another report to show what I want to show. You can forget 30dB anyway, after all 4dB is farrrrrr away from effective by any standard.
Not every RAM material put on display in Zhuhai shows only -4 dbsm. If you’re trying to conclude something about Chinese RAM materials from just that one example you’d be cherry picking.
 

latenlazy

Brigadier
Why do you think so? Aren’t you guys tooo sensitive, hmm?
No, I’m just very particular about arguments that are either being made in bad faith or have sloppy construction. For example, if you can’t cough up numbers for what “particular effectiveness” in L band attenuation are as a comparison we don’t really have a basis for gauging “what” an effective standard is. And if you can’t acknowledge those deficiencies in your argument it’s very difficult to have a productive conversation.
 

SEAD

Junior Member
Registered Member
No, I’m just very particular about arguments that are either being made in bad faith or have sloppy construction. For example, if you can’t cough up numbers for what “particular effectiveness” in L band attenuation are as a comparison we don’t really have a basis for gauging “what” an effective standard is. And if you can’t acknowledge those deficiencies in your argument it’s very difficult to have a productive conversation.
it’s more difficult to have a productive conversation with people believing 4dB is effective for RAM. Anyway, let’s end the meaningless chat here.
 

latenlazy

Brigadier
it’s more difficult to have a productive conversation with people believing 4dB is effective for RAM. Anyway, let’s end the meaningless chat here.
-4 db for an 0.8 mm appliqué may or may not be bad. Assuming attenuation scales linearly with material thickness, which I don’t think is that much of a reach (but you’re free to correct me if I’m wrong) that means -8 db for 1.6 mm or -12 db for 2.4 mm. It really depends on what the function or purpose of the material is.

Do you have a reference point for comparison with other materials? If you don’t, I’m afraid you’re the one encouraging meaningless conversation.
 
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Scchwerter_

Junior Member
Registered Member
“Tom Burbage, then executive vice president for the F-35 program,disclosed the incorporation of “fiber mat” technology, describing it as the “biggest technical breakthrough we’ve had on this program.”

from the same aviationweek report.

“The same as” is physically impossible, but effective is very possible.
Im reasonably sure that the article in question made an effort to stress that the “fiber mat” is not definitely the same as the patent that LM filed. And since LM did not in any way specify how effective the patent is at radar absorption beyond vague words, you’re essentially trying to compare a off-the-shelf export product with something that we 1: don’t know any data of 2: are not sure if is currently used 3: don’t know if is currently practical in an industrial setting.
btw I’m still curious about that -30db figure that you were talking about, if there is a source please locate it and share.
 

Scchwerter_

Junior Member
Registered Member
Also just restating this in case anyone has doubts: RAM coatings are not the predominant cause, or in fact even the major cause of an aircraft being LO. The design of the aircraft plays a much bigger part in reducing its observability. Which is to say we should not confuse how stealthy a jet is with how good at radar absorption its skin is. Saying the very obvious here, but never hurts to clarify I guess?
 

Scchwerter_

Junior Member
Registered Member
I actually went and dug up the patent in question (US20100271253A1).

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On page 21 of the 33-page-pdf there are some descriptions on the bands that the CNT-based materials can absorb, and the wording there implies that it is talking about multiple materials with the same base construction when talking about different bands, not that there is one single CNT-based material that works on every wavelength from 0.1MHz to 60GHz.
 

latenlazy

Brigadier
Also just restating this in case anyone has doubts: RAM coatings are not the predominant cause, or in fact even the major cause of an aircraft being LO. The design of the aircraft plays a much bigger part in reducing its observability. Which is to say we should not confuse how stealthy a jet is with how good at radar absorption its skin is. Saying the very obvious here, but never hurts to clarify I guess?
In theory you probably could get low observable characteristics with just materials alone if they were good enough, but that would be pretty impractical since you would have to literally plaster a plane with it everywhere. That said it’s also probably the case that the better and more general use your materials are the more you can relax some shaping aspects in your design for a target RCS. But overall it’s important to keep in mind that oftentimes a lot of the most powerful absorbers are mostly used to deal with hotspots or sensitive areas and aren’t as good for broad application. So in addition to shaping being more of the first order factor in lowering RCS, we need to discuss when and where a particular material is applied when looking at the efficacy of RAM.
 

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