That is why the layout of the PAK-FA is so special. They managed big bays but placed them one after the other along the longitudinal axis of the plane and in the shadow of the unavoidable, drag-generating nose & cockpit sections, so pretty much got that volume for free. Fuel capacity is granted by the extremely developed blended wing-body design. The rear fuselage usually holds not much fuel in almost any plane, with maybe the F-35 holding a bit more than normal. The problem with the fuel in the F-22 is that it has a very short middle fuselage section, together with volume-eating S-shaped air ducts and outright huge side weapon bays. Together with the low BPR engines, this creates a certain lack of range which poses a challenge if the plane has to operate in a contested airspace of a certain depth, a good reason why PCA is being fast tracked instead of modernizing the 22.
F-22 does have two major fuel tanks in rear fuselage by engine bays where it is much slimmer compared to YF-22 prototype.
First of all, I don’t have any proof and also have not made numbers, good or bad about that speed. But I think others would go along that figure of M1.3 for izd. 117 so I will follow your reasoning.
The drag question: what you say is true but not all the truth, since Cd changes with the speed and decreases notably, well beyond the transonic region. This change depends on the particular design, and judging by the wing sweep for instance, supersonic performance was a big issue for the Su-57, as the patent also confirms. Area rule is very apparent too.
When you get out of transsonic and into supersonic at Mach 1.2 or more drag coefficient does not decrease that much.
Look at even some of the most area ruled aircraft ever made like RA5C and XB-70, these have much better fineness ratio than any 5G fighter.
The issue with izd. 30 and izd. 117 is that the first is not a further evolution of the later or even keeping the same layout, so you cannot estimate its thrust as a pure linear progression from the older model. Not only has it a very much reduced number of stages but most crucially it has been designed specifically for supercruise. This is proven not only by the many times this requirement is argued by officials and designers as the justification for spending even more money after the already modern izd. 117 was completed and tested, but the words of its lead designer confirm the crucial parameter of such an engine, specific thrust, to be the highest available in any engine of that category. So either they have way higher temps and compression than the F119 (improbable) or they have lower BPR.
Think of it this way: what mil thrust does F-22 need to fly 1.82 M? 11-12 tf/engine, to account for detuned specs. Izd 117S, which is a bit worse than 117 but of the same design, 8.8 tf. That is a massive 25% – 35% difference. That level of thrust is similar to what an engine of the F100-AL-31F generation needed to propel 4G jets beyond 2 M. Intakes in the Su-57 are simply huge with the best pressure recovery due to adjustable ramps and relatively straight air ducts, and besides the ram compression will keep adding thrust to the engines as the speed increases. So not so crazy IMHO to think that a carefully designed fighter whose cross-sectional area is not bigger than that of a Flanker can get to that speed with engines capable of 12 or more Tf. The exact number will maybe never known but this estimation makes reasonably good sense to me…
Obviously dynamic thrust is harder to estimate but assuming izd.30 can get twice the dynamic thrust of izd.117, which was already much more optimized for supercruise compare to base AL-31F is questionable. You can’t directly compare afterburning thrust of F100 to military thrust of F119, their dynamic thrust profile will be different since afterburner increases exhaust temperature behind the turbine where the combustion gasses already went through some expansion.
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