SU-57: On hold for a decade

Military aircraft - Post cold war aircraft, including for example B-2, Gripen, F-18E/F Super Hornet, Rafale, and Typhoon.
  • Author
  • Message
Offline

duplex

Senior member

Senior member

  • Posts: 397
  • Joined: 14 Apr 2005, 16:30

Unread post30 Sep 2018, 13:00

marsavian wrote:Russia is claiming the 300 km R-37M aam is in final stages of development and will ultimately equip the Su-57.

https://www.rt.com/news/439553-russia-l ... e-missile/

https://iz.ru/755046/aleksandr-kruglov- ... dlia-su-57


The vast majority of Russian claims are propaganda material for domestic consumption ..

https://www.cnbc.com/2018/05/21/russian ... ter%7Cmain

Big difference between what Russia claims and what it achieves !
Offline

mixelflick

Elite 3K

Elite 3K

  • Posts: 3207
  • Joined: 20 Mar 2010, 10:26
  • Location: Parts Unknown
  • Warnings: 3

Unread post30 Sep 2018, 14:04

marsavian wrote:Russia is claiming the 300 km R-37M aam is in final stages of development and will ultimately equip the Su-57.

https://www.rt.com/news/439553-russia-l ... e-missile/

https://iz.ru/755046/aleksandr-kruglov- ... dlia-su-57


So they'll lug a big, heavy, external weapon around with a 300km range - effective against a stealth target (IF they can find it) at a MUCH shorter range. And in the process, degrade whatever little stealth the SU-57 has.

Brilliant...
Offline

babybat{}.net

Enthusiast

Enthusiast

  • Posts: 82
  • Joined: 08 Sep 2017, 19:16

Unread post30 Sep 2018, 15:16

mixelflick wrote:So they'll lug a big, heavy, external weapon around with a 300km range - effective against a stealth target (IF they can find it) at a MUCH shorter range.


Don't read Russian tabloids)
LRAAM is a weapon against AWACS, JSTARS, Mercury, tankers etc.
Offline

marsavian

Elite 1K

Elite 1K

  • Posts: 1171
  • Joined: 02 Feb 2018, 21:55

Unread post27 Oct 2018, 09:58

Came across quite a detailed appraisal of the Su-57 on Quora which I thought was worth sharing.

https://www.quora.com/Was-the-stealth-f ... ust-a-ruse

Mike McAuliffe -

There are a lot of elements which I would not include in the manner which UA/Sukhoi have in a stealth design. The IRST would have to be completely modified towards an EOSS level with likely placement in the wings to both accomodate supercruise and proper windscreen/nose blending.

You would not generally want to have a separate canopy break in a production stealth airframe.

Production quality overall seems to be going up on the later airframes (which I consider to still be a proper, FSD level, test fleet, unlike the F-35 equivalent which is LRIP Blk.0 production in an unstable testbed configuration…).

But if you note things like this-

At 0:14, you are seeing side look radar as a separate, inset, panel; onventional pitots for the AOA and airspeed system; use of puttied fasteners on the vortex flap as a general lack of design finesse in the LOX or fuel port which should ideally be inside the NLG or weapons bays. Even the chine and the radom shot signs of rough fitting as separate components which could theoretically effect both direct signature and leaks into sensitive RF bays. We literally cast thermoset resin parts which are blended to the airframe skeleton, early in the production process and required the APG-77 (as it’s URR precursor) to have incredible AESA antenna life for the simple reason that you have to cut the nose off to get access to the pressurized antenna volume.

If you move down the airframe, the boundary layer separator inlet and LEVCON fairing could be a little better designed (superior alignment controls, buried behind a splitter or even lost down the DSI intake). I am not a fan of moving structural surfaces on the LE of a stealth platform. It’s bad enough when you do it to the wings but when you put them in a multizone break between upper and lower fuselage chine boundaries, you invite all kinds of creeping/surface wave interactions from both directions up and down the fuselage. I understand their purpose in being there on a wing planform which has more in common with the YF-22 than the F-22 (speed over turn), but you can look at the A/FX and see that we managed to get similar ‘notch’ vortice generation without the potential disaster of an articulated surface in front of an inlet. I suppose it’s better than a canard…

Speaking of turbo paths… Those are some pretty healthy intakes with serious toe out to mask the downstream nacelles and provide decent ram recovery as boundary escape from the fuselage. The problem is that the tunnel inbetween is almost purely vertical which means that, unless you are operating exclusively over a friendly GCI environment, anything lookin up is going to get a multipath return that is simply too much of an inherent design compromise to the aiframe configuration to be ameliorated. Wide pancake for weapons bays = no room for RAM appliques. The YF-23 bypassed this by pushing the engines above the wing and pushing the weapons bays ahead of the airfoil but nothing with a ‘super agility +’ rating is going to be doing that with an almost pure delta sweep of 46.5`.

I would need to have a close look at the jet’s technical drawings to be sure but IMO, their is not enough serpentine in the inlet trunking to mask the engine face, even with the very long ducts and a probable blocker. By itself, this is a disaster for FQ VLO and indicates a serious bias away from VLO towards maximum aerodynamic and weapons system performance (long LRAAM like the Izdeliye 810).

Do the Russians know something about stealth engineering as BVR combat that we don’t? These are serious (MiG-31 level) configurationally permanent compromises which make very little sense when looked at from a pure VLO design standpoint, especially given all the specialist variants of ‘multirole’ (penetrating) ordnance that have been developed specifically for the jet.

The vertical tail fairings, engine nacelles and boat tail fairing are all very tightly packaged. I would expect a lot of edge glint and multi aspect (Mie _and_ Rayleigh) scattering from tunnel effects. I’m not an aerodynamicist but the jet has got a really broad, thick, a$$ end and that’s seldom good when it comes to wavedrag (note: The F-22 is a ‘triumph of thrust over drag’ so it’s not like we are perfect at this either).

Finally, coatings. My understanding is that it’s functionally impossible to unify impedance loadings along multiple panel boundaries and material types and so we paint our jets with a silver based conductive prime coat which treats the entire airframe as a surface duct for travelling waves and then ‘top coat’ over this with something that is nano engineered to have specific RF cancellation behaviors. It is this combination of base-metallic and top RAM coats which gives jets like the F-22 and F-35 their oddly reflective/dusky look.

The camouflage on the Su-57 looks like paint. It’s crudely applied in some areas and it’s very diversity of color patterning means it’s going to be subject to divergent thermal as well as RF behaviors, due to the size of pigment balls. Now, I know the Russians have been pushing really hard into molecular chemistry as their own pursuit of third generation stealth capabilities. There are documentaries covering the Su-57 on Youtube which highlight this ‘Secret Lab Work’ effort. But the jet at the moment does not look like it is using full spectrum integration of the shape-shape-shape+materials paradigm with careful surface designs integrated with optimized coatings specific to RF band (BVR) specific stealth as we now know it.

Quantum ‘Sunflower’ radar? Advanced Opto-Acoustic tracking networks? Or simply a different vision of how 21st Century Air Defense is to be executed in the future? When everyone and their mother’s uncle was maneuvering to end the F-22 program without making too big a deal about it, Michael O’Hanlon of Brookings Institute fame came up with a clever interpretation of number of F-15s ‘at the coal face’ of the 1991 air campaign as something like 90 jets in-theater and 60 available on any given day.

About five years earlier, LMTAS got a ‘note in the night’ which was so worrisome that the VP brought in the engineering staff on the weekend and told them to dump the faceted Su-27 design that was then Lockheed’s leading solution to the ATF problem and replace it with one which would eventually look like a cubist F-15.

IMO, something happened, in the intervening years, that changed the paradigm. It may have been an improved material or system. It may have been a vulnerability to a specific waveform or even something exotic like multistatics or quantum stuff, related to AESA. But stealth got turned on it’s head in that time frame and the idea of penetrating OCA as a HVA specialist sniping asset went with it, to be replaced by something with a more balanced design point as SC&M (Super Cruise & Maneuver) emphasis: the short lunge rather than the long jog.

I find it amazing that the Russians have had a similar epiphanic moment with similar numbers conclusions (60 now, 160 of the ‘second generation’). I do not believe that the AL-41F1 (MiG-1.44, vari-cycle) vs. AL-41 TVS-117 (AL-31FM, Su-35) engine has anything directly to do with it.

It could be economic. The Squeeze consequences to the Crimean and Donbass reactions to Western meddling in Ukrainian politics could really be beginning to effect Russian strategic theory, especially if they foresee a likely war before the 2025–2027 period when the production system is ready.

But I don’t believe that’s the case. The Russians are much better than we are at making quiet progress, using existing systems/upgrades as testbeds for a new design and then integrating established and new systems together without as much fuss as we ‘clean sheet’ always seem to encounter.

I think there has been a major change in the way the warfighter’s are expected to interact and while RFLO still has a considerable part to play in that, it may well be that manned systems are no longer seen as viable guarantors of ‘edge’ sufficient to ensure victory.
Offline

knowan

Active Member

Active Member

  • Posts: 220
  • Joined: 24 Jul 2018, 10:39

Unread post28 Oct 2018, 00:43

marsavian wrote:Came across quite a detailed appraisal of the Su-57 on Quora which I thought was worth sharing.

https://www.quora.com/Was-the-stealth-f ... ust-a-ruse


Quora is 99% sh*t, but there is the occasional post by people that actually know what they're talking about, like this one.
Offline

mixelflick

Elite 3K

Elite 3K

  • Posts: 3207
  • Joined: 20 Mar 2010, 10:26
  • Location: Parts Unknown
  • Warnings: 3

Unread post29 Oct 2018, 14:49

Forget who here said it, but "F-22 is a triumph of thrust over drag"

Really?

It looks plenty sleek to me. Granted the fuselage is boxy but also flat, leading to improved lift. The F-35 is boxy as hell too, and that has plenty of thrust, just not so much relative to weight as the F-22.

I suppose like everything else the drag figures are classified. Thought the real game was lift to drag ratio though?? I could be wrong. Still, mach 1.8 supercruise ain't too shabby (and that's what's been admitted to, not what's classified..
Previous

Return to Modern Military Aircraft

Who is online

Users browsing this forum: zhangmdev and 11 guests