Mover know more about USA stuff. I remember watching good stuff he put out about F-14. But for other thing the guy don’t know or care. Max is less biased and have okay Ish knowledge of other nations toys. So yea if you like USA stuff he is definitely better.
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Oh jesus brother, don’t involve me in shartt’s crap.
Bay cooling ducts route to the exhaust nozzle on quite a few engines. Be it the J79, the J85, or even the AL-51F-1. It’s typically used as a replacement for keel ducts (something that you can see between the engine bay and airbrake fairings on the F-16, or in a simplified duct the entirety of the A-7’s tail) and helps pull the air routed throughout the engine bay for cooling purposes out of the aircraft.
When it comes to most 21st century turbofans and their attempts to mitigate heat by venting it through the engine’s nozzle, it both saves space in ducting and helps mitigate the shock caused by the condi nozzle.
For the Su-57 itself, the intakes can be found at the base of the leading edge of either vert stab. The most recent change in design to incorporate them was pushed in 2017 alongside the original Izd. 30 tests, and it saves a lot more space than incorporating it with the diverter, like the aforementioned F-16 does.
The guy in the comment wasn’t rambling. He was indeed wrong about the F-22 lacking ventilation, as it most certainly has dedicated bay inlet doors, but it doesn’t detract from the fact that his statement was pretty short and simple.
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If you think about it really hard… You may come to the conclusion that the entire aircraft is air-cooled!
You’d have to do a bit of simplification here and there, but anything’s air cooled if you’re travelling fast enough.
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its funny how he said a f16 could beat a su57 in dogfight
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Yeah, but the F22 does that as well. Part of the incoming air captured from the boundary layer control system and turbofan bypass air go all the way to the exhaust and mix with the hot air, again from small puncture holes all over the exhaust structure.
You can see the small punctures better in this video than in images on google.
Videos like this are part of why I don’t trust most things we read online on stealthiness, claims from manufacturer, and numbers from RCS simulations. As one can see, the F22 also has gaps on its structure (look the fitting from the fuselage vs the vertical stabs, the myriad of confusing wedges inside the splitter plate, etc.).
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Very interesting!! You also made a good point on the literature online and on the stealth bit too, most people have NO IDEA how stealth ACTUALLY works. The maintenance of the RAM is so hard!!. I mean look how bad the F-22 is ageing, so many pictures of the pain peeling off and rusting.
And if you travel even faster its air heated! :D
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And that is why Powerful AESA radar need “water” cooling.
Gaps and wedges are unavoidable as perfect tolerance/fits are impossible to achieve on aircraft.
You must have gaps and wedges because the panels have to expand and contract with the very large changes is temperature the aircraft may experience. Gaps are needed to allow for this to occur.
A huge portion of RCS reduction work is done by clever design of every panel/surface to ensure that radar is not reflected back to the receiver.
However, this is not very effective on its own, so every exposed surface is coated in radar absorbing materials to absorb as much radar as possible and prevent it from being reflected in the first place.
Stealth is not about achieving 100% invisibility, It is reducing it to such a level that the aircraft can operate and perform its mission without being detected.
We still need the aircraft to be flyable, and compromises have to be made.
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Sure, so you see the contradiction on theory and reality? F22 and SU57?
There were old articles where LM and ATF people claimed -40 to -70 Dbsm “on a certain angle”, but, as far as we see from all simulations (not only on the F22), those hyper low numbers are on very minor arcs of the skin, like an arc less than a tenth of a degree – if they appear at all.
Then, most F22 simulations (most RCS simulations in general tbh) use very simplified models (nowhere near the detail as in the one posted). Suppose it is true, that RCS is super sensitive to shape, as some claim, and thus minor deviations from the original matter a lot, then most RCS simulations out there are unreliable simply because the models are not super accurate.
As you pointed, gaps and wedges are a reality, but, they also happen to be sources of diffraction. If shape is so important on those sorts of calculations, to the point even a 0.1º in wing sweep makes a difference, then those simplified models just don’t cut it. For comparison, these are some CAD renders from LM themselves, back in the 90s/00s:
As you can see, they’re also “perfect tolerance” models, and look kinda low in polygons (expected for computational power in the 90s). So, can we rely on RCS predictions done on models with the same quality as that? If shape is such a super important factor, my guess would be… no.
But that’s what we mostly see on simulations: things are perfectly air-tight, gaps are absolutely non-existant, and a bunch of other idealized conditions. I can kinda understand using PEC (perfect electrical conductor) for aircraft skin to try isolate shape effect alone, but is it good if shape is wrong and so sensitive to angles? Also, as EM are interferring waves, can you say for sure a specific patch of skin wasn’t deliberately made of metal just to cause wave cancellation from an echo from another part of the airframe, at certain conditions? It’s a lot of “ifs” for such seemingly important factors. Then, reality is 5th gens have composite skin – not gold, not silver, not copper, and certainly not PEC --, edge/wedge/tip treatment with RAM, RAS who knows where and who knows how advanced electronic means of interferring with incoming radar waves.
Then, with all that said, it’s hard to see the claimed -40 to -70db in simulations with airtight models, can we expect a real life model with manufacturing imperfections to achieve the same? Were those claimed numbers coming from their own simulations or from anechoic chamber testing with a 1:1 scale model? The information isn’t clear to that. Many of the reasons given for the SU57/J20 (at occasions even for the F35) lack of stealth can be seen for the F22 on images from that tour video (gaps, weird shapes, possible corner reflectors, etc).
So, again, I see those simulations as mere curiosities, I don’t think they are reliable, nor are the manufacturer numbers nor claims we see online.
Menial gaps in its structure are only relevant to whatever band may be effective in detecting them.
Almost all statements on RCS and EPR state the band tested, and scattering range dictated by the signal. In the case of the F-22, its small imperfections mean little to nothing for its stealth effectiveness.
Real SR-71 moment
Or MiG-25?
Screw it… Let’s move the topic to spacecraft!
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THE SU-57 is good, but its just not up to the levels of the F-22.
That’s the popular opinion but electronically that isn’t the case.
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TBH we will never know, both have strengths and weaknesses, why dont we leave it at that.
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we know the RCS of both planes. the F-22 is stealthier.
No, nobody does.
MY GUY I DONT know if you just don’t know but the rcs of the f-22 is easy to find out its not even classified anymore lol we even know what the cockpit looks like
Tell me the RCS of the Su-57 and F-22.
And also give me some reliable sources.
Wow. The cockpit photo must be top secret.
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What does this have to do with the RCS?
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